System and method for determining structural characteristics of an object

ABSTRACT

The present invention relates generally to a system and method for measuring the structural characteristics of an object. The object is subjected to an energy application processes and provides an objective, quantitative measurement of structural characteristics of an object. The system may include a device, for example, a percussion instrument, capable of being reproducibly placed against the object undergoing such measurement for reproducible positioning. The structural characteristics as defined herein may include vibration damping capacities, acoustic damping capacities, structural integrity or structural stability.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority and benefit of U.S. provisionalpatent application Ser. No. 61/576,982, filed Dec. 16, 2011, entitled“SYSTEM AND METHOD FOR DETERMINING STRUCTURAL CHARACTERISTICS OF ANOBJECT”, and of U.S. patent application Ser. No. 13/163,671, filed Jun.18, 2011, entitled “SYSTEM AND METHOD FOR DETERMINING STRUCTURALCHARACTERISTICS OF AN OBJECT”, the contents of all of which are herebyincorporated by reference in their entirety.

FIELD OF THE INVENTION

This invention relates generally to evaluation of the structuralproperties of an object; and more specifically relates to evaluation ofthe structural characteristics that reflects the integrity of an object;after subjecting to an energy application thereon.

BACKGROUND OF THE INVENTION

When an object is subjected to an impact force, a stress wave istransmitted through the object. This stress wave causes deformations inthe internal structure of the object. As the object deforms it acts, inpart, as a shock absorber, dissipating a portion of the mechanicalenergy associated with the impact. The ability of the object todissipate mechanical energy, commonly referred to as the “dampingcapacity” of the object, depends on several factors, including the typeand structural integrity of the materials making up the object.

There are instruments that are capable of measuring the damping capacityof an object. An example of such an instrument is described in U.S. Pat.No. 6,120,466 (“the '466 patent”), issued 19 Sep. 2000 and entitled“System and Method for Quantitative Measurements of Energy DampingCapacity”. The instrument disclosed in the '466 patent provides anobjective, quantitative measurement of the damping capacity of anobject, referred to as the loss coefficient 17. The energy of an elasticwave attenuates relatively quickly in materials with a relatively highloss coefficient, whereas the energy of an elastic wave attenuatesrelatively slowly in materials with a relatively low loss coefficient.

The damping capacity of an object is an important parameter in a widevariety of applications. For example, in the field of dentistry, when ahealthy tooth is subjected to an impact force, the mechanical energyassociated with the impact is primarily dissipated by the periodontalligament. Changes in the structure of the periodontal ligament thatreduce its ability to dissipate the mechanical energy associated with animpact force, and thus reduce overall tooth stability, can be detectedby measuring the loss coefficient of the tooth.

SUMMARY OF THE INVENTION

The present invention relates to a system and method for measuringstructural characteristics of an object. The object may be subjected toan energy application process and the system is adapted for providing anobjective, quantitative measurement of structural characteristics of theobject after the energy application process. The system and method iscapable of generating more reproducible measurements and better able todetect any abnormalities that may be present in an object.

The present invention further relates to a system and method formeasuring structural characteristics using an energy application tooland includes disposable features for aiding in eliminating or minimizingcontamination of the object undergoing the measurement through transferfrom the system or cross-contamination from previous objects undergoingthe measurements, without interfering with the measurement or thecapability of the system. The system provides a non-destructive methodof measurement with some contact with the object undergoing suchmeasurement without the need for wiping or autoclaving of the energyapplication tool, and at the same time without disposing of the entireenergy application tool. The disposable feature may include a membraneenveloping a part of the system that may come into contact with theobject undergoing the measurement without interfering with thesensitivity, reproducibility, if desired, or general operation of theinstrument to any substantial degree. The membrane itself may or may notcome into contact with the object and may only be protecting the rest ofthe system, including the rest of the energy application tool such asthe part of the tapping rod that normally does not come into contactwith the object. The disposable feature may be used on any existingenergy application tool, such as any percussion tool, and the system mayor may not include a sleeve feature for contacting the object to betested, or a feature for aiding in repositionability

The system may include a device, for example, a percussion instrument,capable of being reproducibly placed directly on the object undergoingsuch measurement for reproducible measurements, and may includedisposable features for aiding in eliminating or minimizingcontamination or cross-contamination of the energy application tool orthe object undergoing the measurement through transfer from the systemor object, or cross-contamination from previous objects undergoing themeasurements without wiping or autoclaving the energy application toolprior to use.

The structural characteristics as defined herein may include vibrationdamping capacities; acoustic damping capacities; defects includinginherent defects in, for example, the bone or the material that made upthe object; cracks, micro-cracks, fractures, microfractures; loss ofcement seal of the object, for example, to the anchor and/or foundation;cement failure between, for example, the object and anchor and/orfoundation; bond failure between, for example, the object and anchorand/or foundation; microleakage, for example, either from the objectionand/or between the object and anchor and/or foundation; lesions; decay;structural integrity in general or structural stability in general. Foran anatomical object, such as a tooth structure, a natural tooth, anatural tooth that has a fracture due to wear or trauma, a natural tooththat has become at least partially abscessed, or a natural tooth thathas undergone a bone augmentation procedure, a prosthetic dental implantstructure, a dental structure, an orthopedic structure or an orthopedicimplant, such characteristics may indicate the health of the object, orthe health of the underlying foundation to which the object may beanchored or attached. The health of the object and/or the underlyingfoundation may also be correlated to densities or bone densities or alevel of osseointegration; any defects, inherent or otherwise; orcracks, fractures, microfractures, microcracks; loss of cement seal;cement failure; bond failure; microleakage; lesion; or decay. Forobjects in general, for example, polymeric composite structuresincluding honeycombs or layered honeycombs or metallic compositestructures; planes, automobiles, ships, bridges, buildings, industrialstructures including, but not limited to power generation facilities,arch structures, or other similar physical structures; such measurementsmay also be correlated to any structural integrity, or structuralstability, such as defects or cracks, even hairline fractures ormicrocracks, and so on.

Additionally, changes in the structure of the tooth that reduce itsability to dissipate the mechanical energy associated with an impactforce, and thus reduce overall tooth structural stability, can bedetected by evaluation of the energy return data as compared to an idealnon-damaged sample.

In one exemplary embodiment, the device may include a handpiece having ahousing with an open end and an energy application tool, for example, atapping rod, or impact rod mounted inside the housing for movement atthe open end. The housing has a longitudinal axis and the energyapplication tool has a length with a resting configuration and an activeconfiguration.

In one embodiment, the resting configuration may be a retracted form andthe active configuration may be an extended form when the energyapplication tool moves axially along the longitudinal axis of thehousing, the retracted form being retracted from or substantiallycoextensive with the open end of the housing. The movement of the energyapplication tool, for example, a tapping rod, may be effected by a drivemechanism mounted inside the housing for driving the tapping rod axiallywithin the housing between a retracted position and an extended positionduring operation. In the extended position, the free end of the tappingrod is capable of extending or protruding from the open end of thehousing.

In another embodiment, the resting configuration may be a formsubstantially parallel to the longitudinal axis of the housing, and theactive configuration may be a form when the energy application tool, forexample, a tapping rod, or impact rod mounted inside the housing formsan acute angle with the longitudinal axis of the housing, such as, forexample, by rocking back and forth about a pivot point on thelongitudinal axis. Thus, the energy application tool oscillates from thesubstantially parallel position to the longitudinal axis of the housingto a position making an acute angle with the longitudinal axis of thehousing at a pivot point. The energy application tool may be held eitherhorizontally or in other positions during measurement, and may have atip portion that is substantially perpendicular to the major portion ofthe tool and maintains a constant length either at rest or at impact.The movement of the energy application tool, for example, a tapping rod,may be effected by a drive mechanism mounted inside the housing fordriving the tapping rod from a substantially parallel position to thelongitudinal axis of the housing to a position making an acute anglewith the axis at a pivot point and back again, while the tip oscillatesup and down in turn. Using this embodiment, measurements may beundertaken at locations which are relatively inaccessible such as, forexample, in the molar area of a patient's teeth.

The drive mechanism may be an electromagnetic mechanism, and may includean electromagnetic coil. In one embodiment, the drive mechanism mayinclude a permanent magnet secured to the back end of the energyapplication tool, for example, the tapping rod, and the magnetic coilmay lie axially behind this permanent magnet. Together with the backpart of the handpiece housing and any electrical supply lines, themagnetic coil forms a structural unit which may be integrallyoperational and which may be, for example, connected to the remainingdevice by a suitable releasable connection, for example, a screw-typeconnection or a plug-type connection. This releasable connection mayfacilitate cleaning, repairing and others.

The energy application tool, such as the tapping rod, is located in thefront part of the housing and the mounting mechanism for the tapping rodmay include frictionless bearings. These bearings may include one ormore axial openings so that the neighboring chambers formed by thehousing and the tapping rod are in communication with one another forthe exchange of air.

In one embodiment, the tapping rod may have a substantially constantcross-sectional construction over its entire length, with a permanentmagnetic ensemble mounted at the end away from the free end, as notedabove. The electromagnetic coil of the driving mechanism may be situatedbehind the other end of the tapping rod, also as noted above, resultingin a relatively small outside diameter for the handpiece. In thisembodiment, the outside diameter of the handpiece housing may besubstantially defined only by the cross-section of the tapping rod, themounting mechanism of the tapping rod in the housing, and the thicknessof the walls of the housing.

In one exemplary embodiment of the invention, the energy applicationtool, for example, a percussion rod or tapping rod may have a frontportion having a separable tip attached to it, which may besubstantially parallel to the majority of the rod or substantiallyperpendicular to the majority of the tapping rod, and a back portionadjacent the drive mechanism. The tip portion may come into contact witha testing surface, such as a patient's tooth or other work surface andmay be connected to the front portion of the tapping rod throughmagnetism. In one aspect, the end of the front portion may have a magnetlocated thereon. In another aspect, the end of the front portion mayhave a magnetic element for holding onto the tip through a magneticforce. In one embodiment, the magnet or a magnetic element may bepresent on the front portion of the energy application tool. In anotherembodiment, the magnet or magnetic element may be present on theseparable tip.

In one embodiment of the invention, the device may include a membranewhich may be integrally formed about the tip of the energy applicationtool assembly so that it substantially covers the entire tip and thehandpiece housing enclosing the rest of the energy application toolassembly. The tip may or may not be separable or need to be disposable.The membrane may be chosen to have a minimal effect on the operation ofthe energy application tool, such as a tapping rod. In one aspect, thedisposable feature may include the membrane with no or one open endfacing the driving mechanism. The connection to the front portion of thetapping rod assembly by the tip, if it is separable, may be formedthrough the magnet and as the tip does not come into contact with thetesting surface, it may be reused. In a further aspect, the membrane maycover the entire tip and includes folds or flutes on both sides of thefront housing enclosing the tapping rod assembly so that it may allowthe tapping rod to extend and contract without tearing the membrane.

In another embodiment of the invention, the disposable feature mayinclude a separate tip and membrane. The membrane may have a hollowinterior with one open end, and a substantially similar shape and sizeto the front portion of the handpiece housing enclosing the energyapplication tool assembly, such as a tapping rod assembly, so that itmay be tightly fitted about or fixed to the front end of the handpiecehousing enclosing the tapping rod assembly with the closed end facingthe separable tip that is connected to the front end of the tapping rod.The membrane does not cover the separable tip so that the separable tipis exposed to the object undergoing measurement and is thereforedisposable. The disposable assembly may be assembled in manufacturingand sold as a unit or assembled in the dental office and soldseparately. In one embodiment, a magnet or magnetic element may bepresent on the front end of the application tool such as a tapping rod.In another embodiment, a magnet or magnetic element may be present onthe separable tip. In one aspect, the separable tip may be connected tothe front end of the tapping rod assembly through the membrane coveringthe front end of the handpiece housing enclosing the tapping rodmagnetically via the magnet or magnetic element at the front end of thetapping rod assembly that is also covered by the membrane. In anotheraspect, the separable tip may be connected to the front end of thetapping rod through the membrane covering the front end of the tappingrod assembly magnetically via the magnet or magnetic element that is onthe separable tip and thus is also exposed and hence disposable.

In a further embodiment of the invention, the energy application tool,for example, a percussion rod or tapping rod may have a front portionthat comes into contact with the testing surface such as a patient'stooth or any other work surface, and a back portion adjacent to thedrive mechanism. The front portion enclosed in a handpiece housing maybe enveloped in a disposable feature, such as a membrane, completely sothat it does not come into contact with the testing surface. In oneembodiment, the front portion of the tapping rod may have a tip whichmay be perpendicular to the majority of the tapping rod and the membranemay have folds or flutes on both sides of the front portion of thehandpiece housing enclosing the tapping rod assembly. The folds orflutes allow the tapping rod to be oscillating from a substantiallyparallel position with the longitudinal axis of the housing of thehandpiece to a position making an acute angle with the longitudinal axisof the housing of the handpiece at a pivot point without tearing themembrane. In another embodiment, the folds or flutes may not be neededwhen the energy application tool moves from a substantially parallelposition with the longitudinal axis of the housing of the handpiece to aposition making an acute angle with the longitudinal axis of the housingof the handpiece at a pivot point if the membrane only covers the tip ofthe tapping rod that is substantially perpendicular to the majority ofthe tapping rod. In one embodiment, in the absence of a sleeve, thedisposable membrane may be retained by a collar. In the presence of asleeve, the collar and sleeve may be integrated and the disposablemembrane may be retained by combined sleeve and collar and portions ofthe sleeve may either be covered by the disposable membrane or bedisposable. In one aspect, the membrane may be held by the sleeve eitherintegrally or removably and both the entire sleeve and membrane may bemade disposable. In another aspect, the membrane may be held by thesleeve either integrally or removably and only the membrane may be madedisposable.

In one aspect, the sleeve may cover the major portion of the housing andthe front portion of the sleeve that comes into contact with the objectmay be separable from the rest and that separable portion may bedisposable. In another aspect, the entire sleeve covering the majorportion of the housing may be made disposable.

The handpiece itself may be tethered to an external power supply or bepowered by an electrical source included inside the housing, such as,for example, a battery, a capacitor, a transducer, a solar cell, anexternal source and/or any other appropriate source.

In one embodiment, communication between the drive mechanism and theenergy application tool, such as the tapping rod, may be via a lead orline of electrically conductive, insulated wire which may be woundspirally in a concentric fashion around the tapping rod and hasspring-elastic properties. This may also allow a minimum spacerequirement with respect to the line management. In addition, a helicalspring, which may be formed by the spirally wound wire, may help toavoid or prevent looping or twisting of the wire connection.

In another embodiment, the communication between the drive mechanism maybe transmitted wirelessly via any suitable wireless connections. Thehelical spring, if present, may be composed of stranded wires having twotwisted individual wires or of a coaxial line. In its loaded condition,the spring may be compressed to such a degree that the force of itsprestress corresponds to the frictional force and opposes thisfrictional force during the forward motion of the energy applicationtool, for example, the tapping rod from the retracted position to theextended position, or from a substantially parallel position to thelongitudinal axis of the housing to a position making an acute anglewith the axis at a pivot. The prestressed path of the spring maytherefore be far greater than the stroke of the tapping rod so thatspring power remains substantially constant over the entire stroke ofthe tapping rod. Any undesirable frictional force of the bearings of themounting mechanism for the tapping rod during the forward motion mayalso be substantially compensated by this spring.

In one aspect, the drive mechanism may include a measuring device, forexample, a piezoelectric force sensor, located within the handpiecehousing for coupling with the energy application tool, such as thetapping rod. The measuring device is adapted for measuring thedeceleration of the tapping rod upon impact with an object duringoperation, or any vibration caused by the tapping rod on the specimen.The piezoelectric force sensor may detect changes in the properties ofthe object and may quantify objectively its internal characteristics.Data transmitted by the piezoelectric force sensor may be processed by asystem program, to be discussed further below.

In another aspect, the drive mechanism may include a linear variabledifferential transformer adapted for sensing and/or measuring thedisplacement of the energy application tool such as the tapping rod,before, during and after the application of energy. The linear variabledifferential transformer may be a non-contact linear displacementsensor. The sensor may utilize inductive technology and thus capable ofsensing any metal target. Also, the noncontact displacement measurementmay allow a computer to determine velocity and acceleration just priorto impact so that the effects of gravity may be eliminated from theresults.

Located at the open end of the housing may be a sleeve. In oneembodiment, the sleeve may attach and/or surround at least a length ofthe free end of the housing and protrudes from the housing at a distancesubstantially coextensive with the end of the tapping rod in itsextended form if the tapping rod moves axially. Thus, the length of thesleeve may be dependent on the length of protrusion of the extendedtapping rod desired. The free end of the sleeve may be placed against anobject undergoing measurement. The contact by the sleeve helps tostabilize the handpiece on the object. In another embodiment, the sleevemay be attached to the end of the housing and being substantiallyperpendicular to it when the tapping rod moves from being substantiallyparallel to making an acute angle with the longitudinal axis of thehousing at a pivot when in operation. The sleeve may be substantiallycylindrical. In a further embodiment, the sleeve may be an extension ofthe housing and being of substantially a half cylindrical shape to allowthe tapping rod to freely move when the tapping rod moves from beingsubstantially parallel to making an acute angle with the longitudinalaxis of the housing in operation. Using this system, measurements may beundertaken at locations which are relatively inaccessible such as, forexample, in the molar area of a patient's teeth.

In one embodiment, the housing may be tapered towards the end surroundedby the sleeve so that the device may have a substantially uniformdimension when the sleeve is attached. In another embodiment, thehousing may have a substantially uniform dimension and the sleeve mayexpand the dimension of the end it surrounds to a certain extent. In afurther embodiment, the sleeve itself may have an inverse taper towardsits free end to increase the flat area of contact with the object.

During measurement, the device may contact the object with the end ofthe sleeve. The contact pressure may vary depending on the operator. Itis desirable that the pressure be consistently applied in a certainrange and that range not be excessive. A sensor, such as a force sensor,may be included in the handpiece for sensing this pressure applicationand may be accompanied by visual signal or digital readout. This sensormay be employed also for assuring that proper alignment against theobject during measurement is obtained.

In one exemplary embodiment, the sleeve includes a tab protruding from aportion of its end so that when the open end of the sleeve is in contactwith at least a portion of a surface of the object undergoing themeasurement, the tab may be resting on a portion of the top of theobject. The tab and the sleeve together assist in the repeatablepositioning of the handpiece with respect to the object, thus resultsare more reproducible than without the tab. In addition, the tab may beadapted for repetitively placed substantially at the same location onthe top of the object every time. In one embodiment, the tab may besubstantially parallel to the longitudinal axis of the sleeve.

In another exemplary embodiment, the sleeve may include a tab and afeature, for example, a ridge, protrusion or other feature substantiallyorthogonal to the surface of the tab on the side adapted for facing thesurface of an object. For example, for teeth, the ridge or protrusionmay nest between adjacent teeth or other orthogonal surface and may thusaid in preventing any substantial lateral or vertical movement of thetab across the surface of the object and/or further aid inrepeatability. The tab may be of sufficient length or width, dependingon the length or width of the top portion of the object so that theridge or protrusion may be properly located during operation. Again, thetab and the feature also aid in the reproducible results than withoutthe tab.

In one aspect, for example, if the object is a tooth, the feature may beshort and of a sufficiently small thickness so that it may fit betweenadjacent teeth. In another aspect, for example, if the object is atooth, the feature may be short and shaped to fit between the topportions of adjacent teeth. In yet another aspect, for example, if theobject is a tooth, and the feature is to rest against the back or frontsurface of the tooth, it may be of a dimension to cover a major portionof the back or front surface while the tab rests on the top surface of atooth.

The tab and/or tab and feature not only serve to aid in repeatablepositioning of the instrument on an object, such as a tooth ormechanical or industrial structure, composites and similar, as mentionedabove, but the tab and/or tab and feature also serve to help keep theobject, such as a tooth or mechanical or industrial structure,composites and similar, as mentioned above, from moving in directionsother than the direction parallel to the energy application or tappingdirection. This helps to minimize any unnecessary disturbances of theobject and/or the foundation it is anchored to and/or complicationswhich may arise from these other disturbances during testing, thusfurther contributing to the sensitivity and/or accuracy of detection.

The end of the sleeve not having the tab protruding from it may be flator substantially flat and the part of the tab in contact with the top ofthe object may be also flat or substantially flat. The tab may extend ina substantially parallel direction from the end of the sleeve. In oneaspect, the tab may be integral with the sleeve for a distance beforeprotruding from the end of the sleeve, keeping substantially thecross-sectional outline of the sleeve after protruding from the sleeve.In another aspect, the tab may protrude uniformly from the top or bottomportion of the sleeve, but with a substantially differentcross-sectional outline from that of the sleeve after protruding fromthe sleeve.

In one exemplary embodiment of the present invention, the tab may have acontact surface substantially mirroring the contour of the surface of anobject to which it comes into contact during use for aiding inreproducibly positioning of the device directly on an object.

In one embodiment, the protruding portion of the tab may have arectangular cross-section. In another embodiment, the protruding portionof the tab may have a slight arched top portion. In yet anotherembodiment, the protruding portion of the tab may conform to the contourof the surface which comes into contact with the object.

In any of the embodiments, the corners of the tab are smooth or roundedor substantially smooth or rounded to avoid any catching on the objectthey may be resting on.

In general, the present device may be useful in making any measurementswhereby vibration is generated through the application of energy, forexample, the striking of, such as a tapping rod, on an object. Theadvantages are that the device may be held in contact with the objectduring the tapping action, in contrast to traditional devices that arenot in contact.

The sleeve and the tab, and/or the sleeve, the tab and the feature, maybe made of any material having vibration damping, acoustic damping, orvibration attenuating properties and the sleeve may be of such length sothat any vibration traveling through the sleeve to the housing of thehandpiece may be substantially attenuated. In one embodiment, the sleeveand the end of the housing adjacent to the sleeve may be made of thesame material. In another embodiment, the sleeve and the end of thehousing it is attached to may be made of materials having similarvibration attenuating properties. In yet another embodiment, the sleeveand the end of the housing it is attached to may be made of differentmaterials. In a further embodiment, the sleeve and the end of thehousing it is attached to may be made of materials having differentvibration attenuating properties. In yet a further embodiment, thesleeve may be made of any material with a vibration attenuating coatingon its surface or surfaces. In still yet another embodiment, the sleeve,tab and/or feature may be made of different materials having similarthermal expansion properties.

In addition, the sleeve and tab and/or the sleeve, the tab and thefeature, may be made of recyclable, compostable or biodegradablematerials which are especially useful in those embodiments that aremeant to be disposed of after one use.

In one exemplary embodiment, a device may include a handpiece having ahousing with an open end and an energy application tool, for example, atapping rod, or impact rod mounted inside the housing for movement atthe open end. The housing has a longitudinal axis and the energyapplication tool has a length with a resting configuration and an activeconfiguration. a sensor positioned inside said housing adapted formonitoring that a proper force is applied when the sleeve rests on theobject. A sleeve may be located at the open end of the housing for adistance, adapted for resting against an object with at least a portionof its open end. A sensor, such as a force sensor may be positionedinside the housing, adapted for monitoring that a proper force isapplied by an operator when the sleeve rests on an object undergoingmeasurement. The sensor may also be employed for assuring that properalignment against the object during measurement is obtained, as notedabove. Additional details of the sensor are described below. The sleevemay or may not have a tab, or a tab with a feature attached to it, asnoted above.

In one exemplary embodiment, the energy application tool, for example, apercussion rod or tapping rod may have a separable tip attached to thefront portion and a back portion adjacent the drive mechanism. Theseparable tip may be the disposable feature of the invention. Theseparable tip may come into contact with a testing surface, such as apatient's tooth or other work surface and be connected to the frontportion of the tapping rod through magnetism. In one aspect, the end ofthe front portion may have a magnet or magnetic element located thereonfor holding onto the tip through the magnetic force. In another aspect,the separable tip may have a magnet or magnetic element thereon forattaching to the front portion of the tapping rod. The disposablefeature may be used without interfering with the measurement or thecapability of the system. The system may or may not include a featurefor aiding repositionability.

In one embodiment, the sleeve and tab and/or sleeve and tab and featurefor aiding in repositionability may be removably connected to thehousing of the handpiece and the disposable feature may include thesleeve and tab, and/or sleeve, tab and feature, and the separable tip.In another embodiment, the disposable feature may include the sleeve andtab, and/or sleeve, tab and feature, and a membrane which may beintegrally formed about the separable tip so that it substantiallycovers the entire tip. The membrane is chosen to have a minimal effecton the operation of the tapping rod and the tip may or may not need tobe disposable. In one aspect, the membrane may cover the entireseparable tip and the connection to the front end of the tapping rod maybe formed through the membrane magnetically. In another aspect, themembrane may have openings on one or both ends and the connection to thetapping rod may be made directly through magnetic forces.

In another embodiment, the sleeve and tab and/or sleeve and tab andfeature may be removably connected to the housing of the handpiece andthe disposable feature may include portion of the front end of thesleeve and tab, and/or portions of the front end of the sleeve, tab andfeature, a separate tip and membrane. The disposable feature may beassembled during manufacturing and sold as a unit, or assembled in thedental office and sold separately or together. The membrane may have ahollow interior with one or two open ends, with a substantially similarshape and size to the rear portion of the sleeve so that the sleeve maybe tightly inserted or fixed to it and the tip may be connected to thefront end of the tapping rod through the magnetic element. In oneaspect, the magnet or magnetic element may be present at the front endof the tapping rod. In another aspect, the magnet or magnetic elementmay be present on the separable tip.

In one exemplary embodiment, the sleeve, tap and/or feature may bereusable. The material used for the construction may be amenable toundergo wiping and or autoclaving.

In another exemplary embodiment, the sleeve, tap and/or feature, as wellas the membrane as described above, or the tip of the tapping rod andmembrane, as described above, may be disposable.

In a further exemplary embodiment, the separable tip and disposablemembrane may be adapted for use in any commercially available percussionhandpieces that are not adapted for contact with an object undermeasurement, that the advantages of the present invention may also berealized.

In yet a further exemplary embodiment, the sleeve, separable tip anddisposable membrane may be adapted for use in any commercially availablepercussion handpieces that are not adapted for contact with an objectunder measurement, so that the advantages of the present invention mayalso be realized.

The evaluation of such structural characteristics mentioned above may bedone in a number of methods, using a number of instruments, for example,a suitable instrument is as described in U.S. Pat. No. 6,120,466 (“the'466 patent”), issued 19 Sep. 2000 and entitled “System and Method forQuantitative Measurements of Energy Damping Capacity”, incorporatedherein by reference. Other instruments and methods may include such asthose disclosed in U.S. Pat. Nos. 6,997,887 and 7,008,385, the contentsof all of which are hereby incorporated by reference in their entirety.These measurements may include using an instrument to measure, for atime interval, energy reflected from the object as a result of thetapping or applying energy, which may include creating a time-energyprofile based on the energy reflected from the object during the timeinterval, and/or evaluating the time energy profile to determine thedamping capacity of the object. Further device may also be used, such asthat disclosed U.S. Pat. Nos. 4,482,324 and 4,689,011, incorporatedherein by reference in their entirety. All these instruments and devicesmay be modified with the present sleeve configuration for repetitiverepositionability.

As mentioned above, the sleeve in any of the above noted embodiments maybe removable. According to one embodiment of the invention, the sleevemay be disposable. According to another embodiment of the invention, thesleeve may be reusable. In one aspect, the disposable sleeve may besterilizable and disposable after multiple uses. In another aspect, thesleeve may be for a one-use, either made of sterilizable ornon-sterilizable material.

The sleeve may be attached to the housing by any suitable attachmentmodes including, but are not limited to, threaded attachment, frictionfit, mating bayonet formations, tongue and groove type formations, snapfit, interesting pin and pinhole formations, latches and otherinterconnecting structures. In one exemplary embodiment, the sleeve andthe housing may be a custom-made threaded system for better fit.

According to another embodiment of the invention, the sleeve may befitted to other commercially available handpieces that are not adaptedfor contact with an object under measurement, so that the advantages ofthe present invention may also be realized.

As mentioned above, the system and method of the present invention isnon-destructive. This is applicable to a system that may or may not havedisposable parts and/or features for aiding in repositionability. Thepresent invention further relates to a system and method for measuringstructural characteristics that minimizes impact, even minute impact onthe object undergoing measurement, without compromising the sensitivityof the measurement or operation of the system. In one embodiment, thesystem includes an energy application tool that is light weight and/orcapable of moving at a slower velocity such that it minimizes the forceof impact on the object during measurement while exhibits or maintainsbetter sensitivity of measurement. In one aspect, the energy applicationtool, for example, the tapping rod, may be made of lighter material tominimize the weight of the handpiece. In another embodiment, the energyapplication tool, for example, the tapping rod, may be made shorterand/or of smaller diameter such that the size of the handpiece may alsobe minimized. In a further embodiment, the system may include a drivemechanism that may lessen the acceleration of the energy applicationtool. For example, the drive mechanism may include a smaller drive coilto lessen the acceleration of the energy application tool, whether ornot it is light weight, and/or smaller in length or diameter, and theimpact force on the object during operation while maintainingsensitivity of measurement. These embodiments may be combined with oneor more of the embodiments described before, including the lighterweight handpiece housing. The speed of conducting measurement may alsobe desirable without increasing the initial velocity of impact so as tominimize impact on the object during measurement. The present inventionrelates to yet another system and method for measuring structuralcharacteristics having a drive mechanism that may decrease the traveldistance of the energy application tool, for example, from about 4 mm toabout 2 mm, while maintaining the same initial velocity at contact andthus, faster measurement is possible without compromising the operationof the system. The system may or may not have disposable parts and/orfeatures for aiding in repositionability and/or lessening impact withfeatures mentioned before.

In any of the systems mentioned above, either with or without lighterweight energy application tool, a shorter or smaller diameter energyapplication tool, or a drive mechanism that may include a smaller drivecoil to lessen the acceleration of the energy application tool, if themeasurement is to be made while a portion of the sleeve is in contactwith the object, the force an operator exerts on the object may also beimportant and may need to be monitored, since, for example, eitherinsufficient or excessive force exerted by an operator may complicatethe measurements, and may even produce less accurate results. In oneembodiment, with any of the embodiments of the invention discussedabove, the handpiece may include strain gauges for measuring the forcesapplied to an object under measurement. A strain gauge, if present, maybe attached or mounted to a cantilever between the handpiece and thesleeve so that pressing the sleeve on the object also deforms thecantilever which is measured by the strain gauge, thus providing a forcemeasurement.

In another embodiment, with any of the embodiments of the inventiondiscussed above, the handpiece may include piezoelectric elements fordirectly measuring the force discussed above.

In some embodiments, multiple strain gauges mounted to a single or toseparate cantilevers may be utilized. The cantilever(s) may also, forexample, be present on a separate component from the rest of thehandpiece or sleeve, such as, for example, on a mounting device.

In one aspect, the force measurement may be connected to a visualoutput, such as lights. In one embodiment, a multiple light system maybe included. For example, a green light may indicate the right amount offorce while a red light may indicate too much force. In anotherembodiment, a one light system may be included. For example, no lightmay give a signal of right amount of force and a red light may give asignal of too much force. In a further embodiment, a flashing red lightmay indicate too much force.

In another aspect, the force measurement may be connected to an audibleoutput. In one embodiment. The audible output may include a beepingsound to indicate too much force. In another embodiment, the audibleoutput may include a beeping sound with a flashing red light to indicatetoo much force. In a further embodiment, the force measurement may beconnected to a voice alert system for alerting too much force. In yet afurther embodiment, the force measurement may be connected to a voicealert system and a flashing red light for alerting too much force.

As noted above, the handpiece may be part of a system that includescomputerized hardware and instrumentation software that may beprogrammed to activate, input and track the action and response of thehandpiece for determining the structural characteristics of the object.The hardware may include a computer for controlling the handpiece andfor analyzing any data collected, for example, the deceleration of theenergy applying tool, for example, the tapping rod, upon impact with aobject. In one embodiment, the handpiece and hardware may communicatevia a wire connection. In another embodiment, the handpiece and hardwaremay communicate via a wireless connection.

In one embodiment, the energy application process of the handpiece maybe triggered via a mechanical mechanism, such as by a switch mechanism.In one aspect, a finger switch may be located at a convenient locationon the handpiece for easy activation by the operator. In another aspect,the switch mechanism may be triggered by applied pressure to the objectthrough the sleeve. In another embodiment, the energy applicationprocess of the handpiece may be triggered via voice control or footcontrol.

Upon activation, the tapping rod extends at a speed toward an object andthe deceleration of the tapping rod upon impact with the object may bemeasured by a measuring device, for example, a piezoelectric forcesensor, installed in the handpiece, and transmitted to the rest of thesystem for analysis. In one aspect, the tapping rod may be programmed tostrike an object a certain number of times per minute at substantiallythe same speed and the deceleration information is recorded or compiledfor analysis by the system.

The sleeve and/or a portion of the housing may also have anantimicrobial coating coated thereon capable of eliminating, preventing,retarding or minimizing the growth of microbes, thus minimizing the useof high temperature autoclaving process or harsh chemicals and mayincrease the kind and number of materials useful as substrates formaking such tools or instruments.

Further, the instrument may be useful in aiding in the selection ofmaterial, such as mechanically biocompatible material, or biomemeticallycompatible material used in the construction of and/or selection of amaterial for an anatomical structure, for example, an implant. Fornormal healthy teeth, the percussive energy generated by mastication isattenuated by the periodontal ligament at the healthy bone-natural toothinterface. However when an implant replaces natural tooth due to damageor disease, the ligament is generally lost and the implant may transmitthe percussive forces directly into the bone. Several materials such ascomposites, gold, zirconia and so on, used to fabricate the implantabutment have been shown to be effective in numerous studies. Whilestudies have demonstrated the survivability of implant restorationsutilizing composite resin, gold or zirconia abutments after constructionof the abutments, there has been no such research done to measure thedynamic response to load of said abutment materials. The instrument ofthe present invention may be used for such purposes and may be useful topredict the suitability or compatibility prior to implantation, or tochoose suitable materials to protect natural teeth adjacent theimplants. Thus, the choice of materials may minimize the disparitybetween the way the implants and natural teeth respond to impact.

Furthermore, the instrument may be useful in aiding in the selection ofmaterial, such as mechanically or chemically durable or compatiblematerial, used in the construction of and/or selection of a materialfor, for example, a plane, an automobile, a ship, a bridge, a building,any industrial structures including, but limited to power generationfacilities, arch structures, or other similar physical structures ordamping material suitable to aid in the construction of such structures.The instrument of the present invention may be used to such purposes andmay be useful to predict the suitability of a material prior toconstruction in addition to detection of cracks, fractures, microcracks,cement failures, bond failures or defect location, etc., after theconstruction.

In addition, the present invention is also useful in distinguishingbetween defects inherent in the material making up the structure orobject, and cracks or fractures, etc., as discussed above due to traumaor wear or repeated loading. Defects inherent in the bone or materialconstruction of an implant, or a physical structure, for example, mayinclude lesions in the bone, similar defects in the implant constructionor manufacturing of polymer, polymer composites or alloys, or metalliccomposites or alloys.

The stabilization of the instrument by the tab or the tab and/or featuremay also minimize any jerky action that may confound the testingresults, for example, any defects inherent in the bone structure orphysical or industrial structure may be masked by jerky action of thetester. This type of defect detection is important because the locationand extent of the defect may impact dramatically upon the stability ofthe implant or physical or industrial structures. Generally when lesionsare detected, for example, in an implant, such as a crestal or apicaldefect, the stability of the implant may be affected if both crestal andapical defect are present. In the past, there is no other way ofgathering this type of information other than costly radiation intensiveprocesses. With the present invention, this type of information may begathered, and may be done in an unobtrusive manner.

In general, the present invention further represents a new form ofprecision of risk assessment in dental health or structural integrity ofphysical structures and an opportunity to diagnose in a new manner. Thepresent invention provides for the administering of kinetic energy tothe specimen, loading and displacement rates that may be determined bythe specimen, deceleration measured upon impact and analysis of dynamicmechanical response for more accurate prediction of cracks, fractures,microcracks, microfractures; loss of cement seal; cement failure; bondfailure; microleakage; lesions; decay; structural integrity in general;structural stability in general or defect location.

Further, multiple indicators of structural integrity, such as LC (losscoefficient) and ERG (energy return graph) may be possible as well aspercussion loads in a critical direction. The present system provides aconvenient and easy way of providing buccal loading and other loadingdirections are possible such as the lingual direction for testing thestructural properties mentioned above.

Buccal loading is important in that it is typically the more dangeroustype of loading encountered by, for example, a tooth. In general,vertical loading induces relatively low stresses in teeth. However,working and/or nonworking motion produces side loading as a result ofthe lateral motion of the jaw and inclined geometries of the occlusalsurfaces of teeth and restorations. This side loading may induce muchhigher stress concentrations at external and internal surfaces and belowthe margin. Thus, using the system of the present invention, such testsmay be easily performed. In short, the system not only is adapted fordetection of structural stability, integrity, cracks, etc., of aprosthetic dental implant structure, a dental structure, an orthopedicstructure, or an orthopedic implant, but may also be adapted for use inthe actual construction and replacement process through testing understresses that may be encountered later after implantation.

Natural loading is typically pulsatile (as opposed to for examplesinusoidal). Muscular, cardiovascular, running, jumping,clenching/bruxing, so on, all may produce loading, for example,pulsatile loading. Percussion loading is pulsatile and thereforephysiological. Percussion loading may be used to measure visco-elasticproperties and detect damage in a structure.

As mentioned above, the present invention provides the ease and speed ofapplication and may be employed to detect and assess microleakage, grossrecurrent decay, loose post/build-up, decay in post space, whether toothis non-restorable, gross decay, near pulp exposure, enamel and dentinalcracks, internal alloy fracture, or even any bioengineering mismatch,any defect that create movement within the structure, and so on in anon-destructive manner. This is also true of industrial or physicalstructures noted above.

In addition, as noted above, the present invention also contributes tothe accuracy of the location of detection of defects, cracks,micro-cracks, fractures, microfracture, leakage, lesions, loss of cementseal; microleakage; decay; structural integrity in cement failure; bondfailure; general or structural stability in general.

The present invention may be further exemplified by the followingdetailed description of the embodiments and drawings shown below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of an embodiment of a system ofthe present invention;

FIGS. 1a and 1b show illustrative embodiments of the tab of the presentinvention;

FIG. 2a illustrates a side perspective view of an embodiment of a sleeveand tab of the present invention;

FIG. 2b illustrates an end perspective view of an embodiment of a sleeveand tab of the present invention;

FIG. 2c illustrates a perspective cross-sectional view of an embodimentof a sleeve and tab of the present invention;

FIG. 2d illustrates an end cross-sectional view of an embodiment of asleeve and tab of the present invention;

FIG. 2e illustrates a side cross-sectional view of an embodiment of asleeve and tab of FIG. 2a of the present invention;

FIG. 3 shows a perspective side view of an embodiment of a sleeve of thepresent invention;

FIG. 3a shows a side view of the embodiment of a sleeve of FIG. 3;

FIG. 3b shows a side view of another embodiment of a sleeve of thepresent invention;

FIG. 3c shows cross-sectional view of the sleeve of FIG. 3b viewed fromthe end of the sleeve;

FIG. 3d shows a cross-sectional view of the sleeve of FIG. 3a viewedfrom the end of the sleeve to be attached to the handpiece;

FIGS. 4a-b illustrate embodiments of the sleeve of the handpiece of thepresent invention;

FIG. 5 illustrates a longitudinal cross-sectional view of an embodimentof a handpiece of the present invention;

FIG. 6 illustrates a cross-sectional view taken along lines III-III ofFIG. 5 of the present invention;

FIG. 7a illustrates a side view of an embodiment of the sleeve and tabof any of FIGS. 2a-d when positioned on an object;

FIGS. 7b and c illustrate embodiments of a top view and front view,respectively, of embodiments of a sleeve and tab of the presentinvention during operation;

FIG. 8 illustrates another embodiment of the sleeve and tab of thepresent invention;

FIGS. 8a and 8b illustrate the sleeve and tab embodiment of FIG. 8during operation;

FIG. 9 illustrates a flow chart of a software program in an embodimentof the invention;

FIGS. 10, 10 a, 11 and 11 a show graphs of an in vitro study of bonedensities of four threaded titanium implants using the system and methodof the present invention;

FIG. 12 shows the force being applied during impact by the tapping rodof an instrument of the present invention;

FIG. 13 shows the dynamic response of the object upon impact by thetapping rod of the instrument of the present invention;

FIGS. 14 and 15 show the formulae used in calculating loss coefficientand energy return graphs of an ideal situation;

FIG. 16 shows an instrument of the present invention;

FIG. 16a shows the loss coefficient and energy return graphs generatedafter impact by the tapping rod of the present invention and how itcompares with the ideal fit;

FIG. 16b shows the graphs of a normal and abnormal structure afternumerous measurement and how it compares with the ideal fit;

FIGS. 17a-h depict a tooth tested with the system and method of thepresent invention and other exiting methods;

FIGS. 18 and 18 a-f show a repeat procedure on a different tooth to thatof FIGS. 17, 17 a-h;

FIGS. 19, 19 a-g depicts 3 teeth tested with the system and method ofthe present invention and other existing methods;

FIGS. 20, 20 a-f shows a tooth and its time percussion response profilebefore and after dental work, using the system of the present invention;

FIGS. 21 and 21 a-b show X-rays and time percussion response profilesusing the system of the present invention of the same tooth;

FIGS. 22 and 22 a show the visual and time percussion response profileusing the system of the present invention of the same tooth;

FIG. 23 shows data from finite element analysis, using a glass rod tosimulate a tooth and a curve created by impact in a finite elementmodel;

FIGS. 24 and 24 b show a defect free composite laminated plate and acomposite laminated sample with a defect placed in the center of thesample between layers, respectively;

FIGS. 24a and c show percussion response graphs for the composites of 24and 24 b, respectively, using Finite Element Analysis;

FIGS. 25 and 25 a show a repeat measurement of composites of FIGS. 24and 24 b;

FIG. 26 shows a picture of an embodiment of the system of the presentinvention;

FIGS. 26a-b show the measuring device of the system of the presentinvention;

FIGS. 27 and 28 show time percussion response profiles generated by thesystem and method of the present invention;

FIG. 29 shows a schematic of an embodiment of the system and instrumentof the present invention;

FIG. 30 shows the cross-sectional view of the front end of an embodimentof the energy application tool of the present invention with separabletip and membrane;

FIGS. 30a and 30b shows the rear view and front view of a tip withretaining magnet of the embodiment of FIG. 30;

FIG. 31 shows the cross-sectional view of the front end of anotherembodiment of a the energy application tool of the present inventionwith separable tip, membrane and sleeve attachment locations shown;

FIG. 32 shows the cross-sectional view of the front end of a furtherembodiment of the energy application tool of the present invention withseparable tip, membrane and sleeve with tab attachment locations shown;

FIG. 33 shows the cross-sectional view of yet another embodiment of theenergy application tool with folded membrane and with separable tip;

FIG. 34 shows a cross-sectional view of a handpiece of the presentinvention including the front end of FIG. 32;

FIG. 34a shows the exploded view of the handpiece of FIG. 34;

FIGS. 34b and b 1 show the exploded view of the front end FIG. 34;

FIG. 34c shows the top view of FIG. 34 without the covers;

FIG. 35 a, b and c shows the handpiece of FIG. 34 in various views;

FIG. 36, a, b, c, and d show the detail exploded view of FIG. 34;

FIGS. 37, 37 a and 37 b show another embodiment of the handpiece of thepresent invention having a perpendicular tip with or without adisposable membrane;

FIG. 38 shows a top view of strain gauge mounting; and

FIG. 38a shows a side profile view of a strain gauge mountingillustrating the direction of deflection.

DETAILED DESCRIPTION OF THE INVENTION

The detailed description set forth below is intended as a description ofthe presently exemplified systems, devices and methods provided inaccordance with aspects of the present invention and is not intended torepresent the only forms in which the present invention may be preparedor utilized. It is to be understood, rather, that the same or equivalentfunctions and components may be accomplished by different embodimentsthat are also intended to be encompassed within the spirit and scope ofthe invention.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood to one of ordinary skill inthe art to which this invention belongs. Although any methods, devicesand materials similar or equivalent to those described herein can beused in the practice or testing of the invention, the exemplary methods,devices and materials are now described.

All publications mentioned herein are incorporated herein by referencefor the purpose of describing and disclosing, for example, the designsand methodologies that are described in the publications which might beused in connection with the presently described invention. Thepublications listed or discussed above, below and throughout the textare provided solely for their disclosure prior to the filing date of thepresent application. Nothing herein is to be construed as an admissionthat the inventors are not entitled to antedate such disclosure byvirtue of prior invention.

The present invention may be used to test objects of practically anysize and shape, to obtain information on their structuralcharacteristics. Such structural characteristics not only include thephysical characteristics of an object or the foundation the object maybe anchored to, but also information as to their locations,compatibility or suitability of a material for use in dental work priorto the actual work, whether a tooth structure is restorable prior to theactual work, whether a restorative procedure is successful, when thetooth structure that underwent any procedure has been remodeled, thelooseness of tooth structure before and after dental work, andcombinations thereof.

The structural characteristics as defined herein may include vibrationdamping capacities; acoustic damping capacities; defects includinginherent defects in, for example, the bone or the material that made upthe object; cracks, micro-cracks, fractures, microfractures; loss ofcement seal; cement failure; bond failure; microleakage; lesions; decay;structural integrity in general or structural stability in general. Foran anatomical object, such as a tooth, a natural tooth, a prostheticdental implant structure, a dental structure, an orthopedic structure oran orthopedic implant, such characteristics may indicate the health ofthe object, or the health of the underlying foundation to which theobject may be anchored or attached. The health of the object and/or theunderlying foundation may also be correlated to densities or bonedensities or a level of osseointegration; any defects, inherent orotherwise; or cracks, fractures, microfractures, microcracks; loss ofcement seal; cement failure; bond failure; microleakage; lesion; decayor combinations thereof. For objects in general, for example, polymericcomposite structures including honeycombs or layered honeycombs ormetallic composite structure; an airplane structure, an automobile, aship, a bridge, a building, industrial structures including, but notlimited to power generation facilities, arch structures, or othersimilar physical structures; such measurements may also be correlated toany structural integrity, or structural stability, such as defects orcracks, even hairline fractures or microcracks, and so on, as notedabove.

For example, in measuring the damping characteristics of teeth, whethernatural or restored, dental implant structures, orthopedic implantstructures, and a variety of other applications where the measurement ofdamping characteristics is utilized, including, but are not limited to,testing airplane structures, composite structures, engineeringmaterials, or the secureness of medical implants, and is particularlyadvantageous in locations that were difficult to access or where liquidcouplants could not be used. Structural integrity, such as the loosenessof a screw, cracks in teeth as well as bone and bone voids, debondedrestorations, and damage in integrated circuit materials. However, theabove list is not intended to be exhaustive.

The present invention provides an effective and repeatable measurementof the structural characteristics of an object, mentioned above.

The object may be subjected to an energy application processes providedvia a handpiece, which forms a part of a computerized system capable ofcollecting and analyzing any data animating from the object. As notedabove, many different structural characteristics may be determined usingthe system and methods of the present invention, including vibrationdamping capacities, acoustic damping capacities, structural integrity orstructural stability of both mechanical and anatomical objects and anyfoundations they may be anchored thereon, as noted above. For ananatomical object, such as a tooth, natural or restored, prostheticdental implant structure, a dental structure, or an orthopedic implant,examples of the structural characteristics as defined herein may includevibration damping capacities, acoustic damping capacities, or structuralstabilities and may indicate the health of the object. The health of theobject, may also be correlated to bone densities or a level ofosseointegration; structural integrity such as defects or cracks, notedabove. For objects in general, such measurements may also be correlatedto their structural integrity such as defects or cracks, also a notedabove. For a physical structure, such as a plane, an automobile, a ship,a bridge, a building or other similar physical structures or dampingmaterial suitable to aid in the construction of such structures,examples of the structural characteristics as defined herein may includevibration damping capacities, acoustic damping capacities, or structuralstabilities and may indicate the health of the structural integrity ofthe object.

The instrument of the present invention may be used to such purposes andmay be useful to predict the suitability of a material prior toconstruction in addition to detection of loss of cement seal; cementfailure; bond failure; microleakage; decay and so on after theconstruction, as mentioned above. In addition, the present invention isuseful in distinguishing between defects inherent in the material makingup the structure or object, and cracks or fractures as discussed abovedue to trauma or wear or repeated loadings. Defects inherent in the boneor material construction of an implant, or a physical structure, forexample, may include lesions in the bone, similar defects in the implantconstruction or polymer, polymer composites or alloys, any type ofceramics, or metallic composites or alloys.

In one embodiment, the handpiece 104 may be, for example, as exemplifiedin FIGS. 1, 35 a, b and c, in the form of a percussion instrument. Thehandpiece 104 may have a cylindrical housing 132 with an open end 132 aand a closed end 132 b. The open end 132 a is tapered as exemplifiedhere, though other configurations are also contemplated. An energyapplication tool 120, for example, a tapping rod 120, may be mountedinside the housing 132 for axial movement, as noted above. The handpiecealso includes a drive mechanism 160, mounted inside the housing 132 fordriving the tapping rod 120 axially within the housing 132 between aretracted position 128 and an extended position 129 during operation. Inthe extended position 129, the free end of the tapping rod 120 extendsor protrudes from the open end 132 a of the housing 132, as shown. Thedrive mechanism 160 may include an electromagnetic coil 156, as shown inFIG. 5, to be discussed further below. In one aspect, the tapping rod120 may have a substantially constant cross-sectional construction overits entire length and has a permanent magnetic ensemble 157 mounted atthe end away from the free end. The electromagnetic coil 156 of thedrive mechanism 160 may be situated behind the other end of the tappingrod 120, resulting in a relatively small outside diameter for thehandpiece 104.

The mounting mechanism for the energy application tool 120, for example,tapping rod 120 may be formed by bearings 1003 and 1004, as shown inFIG. 6, for receiving or supporting the tapping rod 120 in a largelyfriction-free manner. In one example, the housing 132 may be about 150mm long and about 15 mm thick. The magnetic or propulsion coil 156 maybe situated in the housing 132 adjacent to the permanent magnet 157 andis axially behind the permanent magnet 157. The magnetic coil 156 andthe permanent magnet 157 form a drive for the forward and return motionof the tapping rod 120. The drive coil 156 may be an integral componentof the housing 130 and may be connected to a supply hose or line 1000.

The two bearings 1003 and 1004 may be substantially frictionless and mayinclude, as shown in FIG. 6, a plurality of radially inwardly extendingridges separated by axial openings 1400. The axial openings 1400 of thebearing 1003 allow the movement of air between a chamber 1500 which isseparated by the bearing 1003 from a chamber 1600, which chambers areformed between an inner wall surface of the housing 132 and the tappingrod 120. Air movement between these chambers 1500 and 1600 may thuscompensate for movement of the tapping rod 120.

Referring again to FIG. 1, a sleeve 108 is positioned towards the end132 a and extending beyond it. The sleeve 108 envelops the end of thehousing 132 a and is flattened at its end 116 for ease of positioningagainst a surface of an object 112 during operation. The sleeve 108 hasa tab 110, as shown in FIG. 2a , protruding from a portion of its end116, so that when the open end 116 of the sleeve 108 is in contact witha surface of the object 112 undergoing the measurement, the tab 110 maybe resting on a portion of the top of the object 112, as shown here inthe FIGS. 6, 26 a and 26 b. The tab 110 and the sleeve 108 may bothassist in the repeatable positioning of the handpiece 104 with respectto the object 112 and the tab 110 may be placed substantially at thesame distance from the top of the object 112 every time for betterreproducibility. This can be seen better in FIGS. 2b, 2c, and 2d , FIGS.7a-d , or FIGS. 26a and b , though the object 112 is not specificallyshown in FIGS. 2b-d . As noted above, the object may include ananatomical structure or a physical or industrial structure, though ananatomical structure is shown in the figures mentioned here.

The end 116 of the sleeve 108 not having the tab 110 protruding from itis flat or substantially flat, as shown in FIGS. 1, 2 a, 2 b, 2 c and 26b, and the part of the tab 110 in contact with the top of the object 112is also flat or substantially flat, as shown in FIGS. 2a, 2b, 2c and 26b. The tab 110 may extend in a substantially parallel direction from theend of the sleeve 108, as shown in FIGS. 2a, 2b, 2c and 29b . In oneaspect, the tab 110 may be integral with the sleeve 108 for a distancebefore protruding from the end of the sleeve 108, as shown in FIG. 2b ,keeping substantially the cross-sectional outline of the sleeve 108,before and after protruding from the end 116 of the sleeve 108. In thisembodiment, the protruding portion of the tab 110 may have an arched topportion, as shown in FIG. 2b . In another aspect, the tab 110 mayprotrude from the top of the sleeve 108, not keeping the cross-sectionaloutline of the sleeve 108, before and after protruding from the end 116of the sleeve 108, as shown in FIGS. 2a and 2c . In this embodiment, theprotruding portion of the tab 110 may have a rectangular cross-section,as shown in FIGS. 2c and 26b . In any of the embodiments, the corners ofthe tabs 110 are smooth or rounded or substantially smooth or rounded toavoid any catching on the object 112 they may be resting on, as shown inFIG. 1a . In other embodiments, the tab 110 may be smooth, though thecorners may not necessarily be rounded, as shown in FIG. 1b . In afurther embodiment, as shown in the cross-sectional FIG. 2d , thecross-section of the tab 110 does not extend outside the peripheral ofthe cross-section of the sleeve 108.

FIGS. 3 and 3 a show a perspective side and side view of an embodimentof a sleeve 108 of the present invention. In this embodiment, the sleeve108 is tapered towards the free end 116 with a threaded portion 116 afor attachment to the open end of the housing 132 a. FIG. 3d shows across-sectional view of the sleeve of FIG. 3a viewed from the end of thesleeve to be attached to the handpiece 104.

In another embodiment, the sleeve 108 may be substantially non-taper, asshown in FIG. 3b . In this embodiment, the cross-section of the end ofthe sleeve 108 is substantially round, as shown in FIG. 3 c.

In these embodiments, the sleeve 108 may be attached to the handpiece104 by means of threads 116 a. The threaded portion 116 a may have adimension that allows for secured attachment.

In FIGS. 4a-b , other embodiments of the sleeve 108 of the handpiece 104are shown. In FIGS. 4a and 4b , a polymer sleeves 108 features flattenedtips 116 approximately orthogonal to the object 112 surface to furtherassist with the alignment of the handpiece 104. In FIG. 4b , the outerdiameter is at least several times larger than the inner diameter of thesleeve 108. Other shapes and configuration of the sleeve 108 may bepossible, so long as the shape or form used assists with theapproximately orthogonal alignment of the handpiece 104 and attenuatedvibrations from the object 112 caused by the measurement procedure thatmight travel through the sleeve 108 and into the housing 132 of thehandpiece 104 where sensitive measurements are being taken.

FIG. 7a illustrates a side view of the sleeve 108 and tab 110 of any ofthe embodiments of FIGS. 1a-b and 2a-2d when positioned on an object 112during operation. The sleeve 108 touches an object 112, such as a tooth,while the tab 110 rests on the top of the tooth 112, as shown in FIGS.7b and c . The surface of the tab 110 in contact with the object 112 maybe contoured to be better positioned on the top of a tooth 112 or it maybe flat. FIGS. 7b and c illustrate embodiments of a top view and a frontview, respectively of embodiments of a sleeve and tab of FIGS. 1a and 1bduring operation, respectively.

In other embodiments, the sleeve 108 may include a feature 111, forexample, a ridge, protrusion or other similar features substantiallyorthogonal to the surface of the tab 110 on the side facing the surfaceof the object 112, as shown in FIG. 8. For example, for teeth, the ridgeor protrusion may nest between adjacent teeth and may thus aid inpreventing any substantial lateral movement of the tab 110 across thesurface of the object 112, as shown in FIG. 8a or resting on anorthogonal surface, such as the inside surface of the tooth to betested, as shown in FIG. 8b . The sleeve 108 having a tab 110 andfeature 111 may further aid in the repeatability of positioning theenergy applying tool such as the tapping rod 120 on the object 112. Forthe embodiment of 8 a, the tab 110 may extend from the sleeve at asufficient length to enable the ridge or protrusion 111 to rest properlybetween the adjacent teeth. For the embodiment of 8 b, the tab 110 maybe of a sufficient width to enable the ridge or protrusion 111 to restproperly on the inside surface of the tooth to be tested.

In one aspect, for example, if the object 112 is teeth, the feature 111may be short and of a sufficiently small thickness so that it may fitbetween adjacent teeth 112. In another aspect, for example, if theobject 112 is a tooth, the feature 111 may be short and shaped to fitbetween the top portions of adjacent teeth 112. In yet another aspect,for example, if the object 112 is a tooth, and the feature 111 is torest against the back surface, it may be of a dimension to cover a majorportion of the back surface.

For other objects 112, the feature 111 may be shaped accordingly or of adimension suitable for the object 112.

To facilitate the operation of the handpiece 104, the sleeve 108 may bemade of any material having vibration attenuating properties and may beof such length so that any vibration traveling through the sleeve 108 tothe housing 132 of the handpiece 104 may be attenuated. In oneembodiment, the sleeve 108 and/or the tab 110, and the end of thehousing 132 b the sleeve 108 is attached to may be made of the samematerial. In another embodiment, the sleeve 108, and/or the tab 110, andthe end of the housing 132 b the sleeve 108 is attached to may be madeof materials having similar vibration attenuating properties. In yetanother embodiment, the sleeve 108 and/or the tab 110 and the end of thehousing 132 b the sleeve 108 is attached to may be made of differentmaterials, for example, the housing 132 may be made of metal orcomposite, while the sleeve 108 and/or tab 110 may be made of a polymeror composite. In a further embodiment, the sleeve 108 and/or tab 110 andthe end of the housing 132 b the sleeve 108 is attached to may be madeof materials having different vibration attenuating or dampingproperties. In any of the embodiments mentioned above, the feature 111,whether it is a protrusion, a ridge or other similar features orfeatures having similar functionalities, if present, may also be made ofsame materials as the sleeve 108.

In general, it may be desirable for the sleeve 108 to have sufficientrigidity such that it may consistently fit over or into a handpiecehousing 132 and may not collapse during use. If multiple uses arecontemplated, the sleeve 108 may generally be constructed to withstandmultiple sterilization procedures, such as by autoclave, if desired,unless a disposable covering is used, as discussed below. In otherembodiments, the sleeve 108 may be disposable, along with disposablecoverings, if used, as discussed below, and thus may be constructed ofany material that may be formed into a sleeve 108. Examples ofappropriate materials may include, but are not limited to, for example,a polymer that may be molded, thermoformed or cast. Suitable polymersinclude polyethylene; polypropylene; polybutylene; polystyrene;polyester; polytetrafluoroethylene (PTFE); acrylic polymers;polyvinylchloride; Acetal polymers such as polyoxymethylene or Delrin(available from DuPont Company); natural or synthetic rubber; polyamide,or other high temperature polymers such as polyetherimide like ULTEM®, apolymeric alloy such as Xenoy® resin, which is a composite ofpolycarbonate and polybutyleneterephthalate, Lexan® plastic, which is acopolymer of polycarbonate and isophthalate terephthalate resorcinolresin (all available from GE Plastics); liquid crystal polymers, such asan aromatic polyester or an aromatic polyester amide containing, as aconstituent, at least one compound selected from the group consisting ofan aromatic hydroxycarboxylic acid (such as hydroxybenzoate (rigidmonomer), hydroxynaphthoate (flexible monomer), an aromatic hydroxyamineand an aromatic diamine, (exemplified in U.S. Pat. Nos. 6,242,063,6,274,242, 6,643,552 and 6,797,198, the contents of which areincorporated herein by reference), polyesterimide anhydrides withterminal anhydride group or lateral anhydrides (exemplified in U.S. Pat.No. 6,730,377, the content of which is incorporated herein by reference)or combinations thereof. Some of these materials are recyclable or bemade to be recyclable. Compostable or biodegradable materials may alsobe used and may include any biodegradable or biocompostable polyesterssuch as a polylactic acid resin (comprising L-lactic acid and D-lacticacid) and polyglycolic acid (PGA), polyhydroxyvalerate/hydroxybutyrateresin (PHBV) (copolymer of 3-hydroxy butyric acid and 3-hydroxypentanoic acid (3-hydroxy valeric acid) and polyhydroxyalkanoate (PHA)copolymers, and polyester/urethane resin. Some non-compostable ornon-biodegradable materials may also be made compostable orbiodegradable by the addition of certain additives, for example, anyoxo-biodegradable additive such as D2W™ supplied by (SymphonyEnvironmental, Borehamwood, United Kingdom) and TDPA® manufactured byEPI Environmental Products Inc. Vancouver, British Columbia, Canada.

In addition, any polymeric composite such as engineering prepregs orcomposites, which are polymers filled with pigments, carbon particles,silica, glass fibers, or mixtures thereof may also be used. For example,a blend of polycarbonate and ABS (Acrylonitrile Butadiene Styrene) maybe used for the housing 132 and sleeve 108. For further example,carbon-fiber and/or glass-fiber reinforced plastic may also be used.

Synthetic rubbers may be, for example, elastomeric materials and mayinclude, but not limited to, various copolymers or block copolymers(Kratons®) available from Kraton; Polymers such as styrene-butadienerubber or styrene isoprene rubber, EPDM (ethylene propylene dienemonomer) rubber, nitrile (acrylonitrile butadiene) rubber, and the like.

In some embodiments, the sleeve 108 and/or housing 132 may also be madeof metallic and/or ceramic material(s) which may further be coatedand/or treated with a suitable material, such as a polymer or compositeas above. For example, a metallic and/or ceramic material may beutilized that may be substantially vibrationdampening/absorbing/reflecting. A visco-elastic and/or other coating mayalso be employed such that vibrations and/or other mechanical energy maynot translate into metallic and/or ceramic components of the sleeve 108and/or housing 132.

In one embodiment, titanium and titanium alloys such as nickel-titanium,may be used for the sleeve 108 and/or housing 132, orcomponents/portions thereof.

In another embodiment, piezoelectric materials, such as piezoelectricceramics, may be utilized. Piezoelectric materials may generally beutilized to convert mechanical energy into electrical energy.

In one specific embodiment of the invention, the polymer sleeve 108 ofthe handpiece 104 extends out so that the distance from the tip 116 ofthe polymer sleeve 108 in contact with the specimen 112 to the head 128of the tapping rod 120 in its retracted stationary position rangesgenerally from, for example, about 3.5 millimeters to about 5.5millimeters, and more for example, about 3.75 millimeters to about 4.5millimeters. In one exemplary embodiment, the distance from the tip 116of the polymer sleeve 108 of the handpiece 104 in contact with thespecimen 112 to the head 128 of the tapping rod 120 in its retractedstationary position may be about 4 millimeters. These measurements ofthe tapping rod 120 are simply exemplary and are not limiting. Thepolymer sleeve 108 length in one embodiment is dependent upon the lengthof the tapping rod 120 and the total distance that the tapping rod 120can travel when activated without a significant degradation in forwardprogress due to friction and gravity.

As noted above, the sleeve 108 may be removable and may be attached tothe housing 132 in any threaded attachment, friction fit, mating bayonetformations, tongue and groove type formations, snap fit, internestingpin and pinhole formations, latches and other interconnectingstructures. In one exemplary embodiment, the sleeve and the housing maybe a custom-made threaded system for better fit.

In one exemplary embodiment, the other end 136 of the polymer sleeve 108may be threaded 116 a so that it connects to the handpiece housing 132with a similar threading, as illustrated in FIG. 3. The plane includingthe specimen end 116 of the polymer sleeve 108 is approximatelyorthogonal to the axis of the handpiece housing. Also, the surface areaof the specimen end 116 of the polymer sleeve 108 may be sufficientlylarge. This and the tab 110 assist in the approximately orthogonalplacement and position stability of the handpiece 104. In oneembodiment, the outer diameter of the specimen end of the tip 116 isgenerally within the range of, for example, from about 6 millimeters toabout 14 millimeters, and more for example, within the range of fromabout 8 millimeters to about 11 millimeters. In one exemplaryembodiment, the outer diameter is about 9.5 millimeters. The innerdiameter of the specimen end of the tip 116 is generally within therange of, for example, from about 3 millimeters to about 6 millimeters,and more for example, within the range of from about 4 millimeters toabout 5 millimeters. In one exemplary embodiment, the inner diameter isabout 4.7 millimeters.

The sleeve may also have varying inner diameters which decreases fromwhere the sleeve is threaded 136 to the specimen end 116 of the sleeve108. FIG. 1 shows one embodiment where the polymer sleeve 108 has threediscrete inner diameters. Other embodiments have more or less than threeinner diameters, with one embodiment having a continuously, decreasinginner diameter from where the polymer sleeve was threaded 136 to thespecimen end 116 of the polymer sleeve 108. Decreasing inner diametersmay help guide the tapping rod 120 to strike the specimen 112 in aconsistent location and at a consistent angle of inclination. The sleeve108 with the tab 110 may provide greater accuracy and precision ofpositioning on an object 112. For example, a polymeric sleeve 108 havinga damping capacity and of such length so as to attenuate any stresswaves that might interfere with the measurement procedure enables thetip 116 of the polymer sleeve 108 to be placed directly against theobject 112 during operation. By placing the tip 116 of the polymersleeve 108 of the handpiece 104 directly against the object 112 has theadvantage of keeping the distance between the object 112 and the tip 116of the sleeve 108 of the handpiece 104 and the positioning of the tip116 of the sleeve and a surface of the object 112 to be anchored furtherby the tab 110, and feature 111, if present, be substantiallyconsistently the same, resulting in better data reproducibility andgreater accuracy. This capability eliminates the guessing of distanceand positioning and eliminates errors due to, for example, the patient'shead or the operator's hand shaking ever so slightly during themeasurements.

In one embodiment of the present invention, the tip 116 of the sleeve108 with the tab 110 of the handpiece 104 is positioned directly on thespecimen 112 to provide the capability of recreating consistent andaccurate measurements essentially independent of the evaluations of theoperator and the slight movements in the specimen 112, if present.

In another embodiment, Also, the tip 116 of the sleeve 108 with the tab110 and feature 111 of the handpiece 104 is positioned directly on thespecimen 112 to provide the capability of recreating consistent andaccurate measurements essentially independent of the evaluations of theoperator and the slight movements in the specimen 112, if present.

Further, the resting of tip 116 and the tab 110, or the tab 110 andfeature 111 of the sleeve 108 directly on the object 112 also make iteasier for the operator to hold the handpiece 104 steady and to maintaina consistent distance between the tip 116 of the sleeve 108 and theobject 112 while measurements are being made. The sleeve 108 which has aflattened tip 116, as shown in FIG. 1, further assists in aligning ofthe handpiece 104 approximately orthogonal to the surface of the object112 when the tip 116 is placed in contact with the object 112.Self-alignment through contact between the tip 116, the tab 120, and theobject 112, or the tip 116, the tab 110 and feature 111, results in moreaccurate and precise measurements with the angle at which the tappingrod 120 strikes the object 112 being kept constant both during themeasurements and in subsequent measurements.

In addition, the use of a polymer or other material having vibrationattenuating properties for the sleeve 108 of the handpiece 104 may alsoresult in a cleaner signal by keeping stress waves from propagating upthe housing 132 of the handpiece 104. In one exemplary embodiment, PTFEmay be used as the sleeve 108. In another embodiment, polyoxymethylenemay be used for the sleeve 108. PTFE and polyoxymethylene may beautoclavable and of sufficiently high damping capacity to attenuatestress waves from the object 112. The sleeve 108 material may generallyhave a damping capacity as represented by its loss coefficient, rangingfrom about, for example, 0.03 to about 0.2, and more for example, withinthe range of from about 0.06 to about 0.1. In one exemplary embodiment,the loss coefficient may be about 0.08. PTFE also has the advantage ofbeing a solid lubricant which reduces friction between the sleeve 108and the tapping rod 120 as the tapping rod 120 travels back and forthduring the measurement procedure.

With the flattened tip 116 and the tab 120 of the sleeve 108 whichself-aligned itself with the object 112, the operator is aided inkeeping the handpiece 104 approximately horizontal to the ground andapproximately orthogonal to the surface of the object 112 undergoingmeasurement. The handpiece 104 may also have a level indicator 140attached to the housing 132 of the handpiece 104 to further assist theoperator in holding the handpiece 104 approximately horizontal duringtesting. In one embodiment of the present invention, the level indicator140 may include an air bubble 144 trapped in a liquid held in atransparent casing. The user simply keeps the air bubble 144 centeredbetween two marks 148 and 152 in the middle of the transparent casing toassure that the handpiece 104 is in an approximately horizontalposition.

Returning again to FIG. 1, the handpiece may be part of a systemincluding a drive mechanism 160 that may include an piezoelectric forcesensor 160 a, a system hardware 164, for example, a computer 164 havinghigh speed data acquisition capability that may be effected by a highspeed data acquisition board. In one embodiment, a sixteen bitanalog-to-digital channel on a data acquisition card housed in thecomputer 164 may be used. In another embodiment, a purely digitalchannel may be used. In FIG. 1a , the drive mechanism 160 may include alinear variable differential transformer 160 b for sensing and measuringthe displacement of the energy application tool such as the tapping rod120, as shown in FIGS. 1 and 1 a, before, during and after theapplication of energy. The linear variable differential transformer 160b may be a non-contact linear sensor. The sensor may utilize inductivetechnology and thus capable of sensing any metal target.

In one embodiment, the energy application process of the handpiece 104may be triggered via a mechanical mechanism, such as by a switchmechanism 140, for example, as shown in FIG. 1, a finger switch locatedat a convenient location on the handpiece for easy activation by theoperator.

In another embodiment, the energy application process of the handpiece104 may be triggered via a foot control.

In a further embodiment, the energy application process of the handpiece104 may be triggered, for example, via voice control. The voice controlmay be coupled to an electrical control device. The electrical controldevice may include a microprocessor and a switch such as anelectromechanical switch or a solid state switch. An electronic voicecontrol circuit technology, similar to the technology used in electronicdevices such as toys, cell phones, automobiles and other consumerelectronics, may be used to activate the energy application process. Ina still further embodiment, the energy application process of thehandpiece 104 may be triggered via remote wireless control. The remotewireless control may be coupled to the switch mechanism 140 which mayinclude a microprocessor and a switch such as an electromechanicalswitch or a solid state switch. The switch may be activated throughinfrared radiation or through wireless radio signals or through lightfrom the visible portion of the electromagnetic spectrum.

In one exemplary embodiment, to commence the testing of an object 112,the tip 116 of the sleeve 108 of the handpiece 104 is placed against thespecimen 112 and the tapping rod 120 inside the handpiece 104 isactivated with the push of a finger switch 124 located on the handpiece104, as shown in FIG. 1.

Upon activation of the finger switch 124 or other switches on thehandpiece 104, a foot control, voice or wireless control, a movabletapping rod 120 is driven by a propulsion coil 156 through an orifice inthe sleeve 108 to impact the object 112, for example, sixteen times infour seconds. As the tapping rod 120 moves, a magnet 157 located on thetapping rod 120 is displaced with respect to a measuring coil 158. Theacceleration of the tapping rod 120 may be measured by an piezoelectricforce sensor 160 a, or the displacement of the tapping rod 120 may besensed and measured by the linear variable differential transformer 160b. During operation, after application of energy, such as tapping withthe tapping rod, when the measurement is being made by the piezoelectricforce sensor 160 a, signals corresponding to the shock wave resultingfrom such impact are collected and sent to the computer 164, as shown inFIG. 1. In one embodiment, a piezoelectric force sensor 160 a may beused to produce signals corresponding to the shock wave resulting fromeach impact. In one aspect, a sixteen bit analog-to-digital converterchannel on a data acquisition card housed in a computer 164 may be used.In such embodiments, the computer 164 operates at a sampling rate of atleast about 800 kHz; although in other embodiments, the computer 116 mayoperate at a sampling rate of at least about 600 kHz; more for example,a sampling rate of at least about 500 kHz may be used. The signalsgenerated by the piezoelectric force sensor 160 a may be provided to adata acquisition board housed in the computer 164 via anyinstrumentation interface. In one aspect, the signals may be transmittedfrom the piezoelectric force sensor 160 a to the computer 164 via acoaxial cable 168 to the high speed data acquisition card. In anotheraspect, the instrumentation interface may include a signal conditionerand an independent power supply. In yet another aspect, a modifiedembodiment of the instrumentation interface may be incorporated withinthe computer 164.

Software stored in the computer 164 acquires and analyzes, for example,ten of the sixteen impacts to quantitatively determine the structuralcharacteristics, for example, damping capacity or other above listedcharacteristics of the object 112 or its surrounding or foundation towhich it is attached. Typically, three to ten impacts are sufficientlyadequate for sampling of the loss coefficient for a given object, forexample. For example, in one embodiment, the tapping rod 120 impacts theobject 112 approximately sixteen times in a period of four seconds. Inother embodiments, faster or slower impact repetition rates are used. Inan exemplary embodiment, the tapping rod 120 is driven by one or morepropulsion coils 156 electronically activated by a finger switch (notshown), or wireless control, although the propulsion coils 156 can beactivated remotely in other embodiments, as noted above.

When the tapping rod 120 impacts the object 112, some of the kineticenergy of the tapping rod 120 is converted to mechanical energypropagating through the object 112 as a stress wave. Most of theremaining of the kinetic energy is converted (dissipated) to heat, asdictated by the loss coefficient and structure of the object 112. Aportion of the propagated mechanical energy is reflected back to thetapping rod 120, where it can be detected by a piezoelectric forcesensor 160 a mounted within the housing 106. The piezoelectric forcesensor 160 a produces signals that correspond to the reflectedmechanical energy resulting from the impact between the tapping rod 120and the object 112.

In an illustrated embodiment, the computer 164 may include virtualinstrumentation software capable of analyzing the signals received fromthe piezoelectric force sensor 160 a. A wide variety of different typesof data acquisition software can be used to acquire data from thepiezoelectric force sensor 160 a. In one embodiment, customized dataacquisition software developed using the LabVIEW programmingenvironment, available from National Instruments (Austin, Tex.), may beused, although other programming environments can be used in otherembodiments.

After the signals are received from the piezoelectric force sensor 160a, the data processing software is capable of quantitatively measuringthe characteristics desired, for example, damping capacity of the object112, which may often be expressed in terms of the loss coefficient 17.For a series of impacts, as described above, several calculations of thedamping capacity may be performed. For example, in one embodiment thetapping rod 120 impacts the object 112 sixteen times, and the dampingcapacity of the object 112 may be calculated for ten of the sixteenimpacts. In such embodiments, the standard deviation of the dampingcapacity measurements can be calculated, thereby providing the user withan indication of the accuracy of the measurements. Specifically, if thehandpiece 104 is not properly aligned with the object 112, or if anothersource of error is introduced into the measurement process, this errorwill likely manifest itself in the form of a elevated standard deviationof a series of damping capacity measurements. The various embodiments ofany part of the system, such as the sleeve with the tab and/or featurediscussed above may be used in making any testing or measurement of anystructural characteristics of any of the objects previously discussed.

As noted above, the present invention has applications also in thedetection of internal damage such as microcracking, fracture,microfracture and delamination in composite structures and otherengineering materials. Composites are generally more susceptible todamage development than unreinforced metals, particularly when they areunder stresses that approach the tensile strength of the material. Thepresent invention is useful for detecting damage through nondestructivetesting in composite materials and structures.

FIG. 9 shows a flowchart 300 of one exemplary embodiment of softwareprocedure. After the program is loaded and executed 304, the next step308 determines whether calibration is needed. If a familiar testingconfiguration is to be implemented, then the program loads previouslydetermined calibration values stored in a file 312. A calibration filecan be chosen from among the many previous calibration files stored inmemory. If a new testing configuration is being used, then a calibrationprocedure 316 was completed and the new calibration values stored in anew file before the new calibration values are implemented at step 320.In the next step 324, the program accepts the signal from thepiezoelectric force sensor 324, converted the signal into energy data328, displaying the energy data in graphical and textual form on thecomputer monitor 332, calculating n, for example, the loss coefficient,.eta. 336; and/or calculate standard deviation of the loss coefficientmeasurements and Normalized Ideal Fit Error; and then either discardingor saving into a file the energy data depending upon the discretion ofthe operator 340.

Then, the operator chooses from among three options: make moremeasurements in that series of measurements 357; commence a new seriesof measurements 358, or exit the program 359. In one embodiment of theprogram, a graphical user interface displays the above three optionsfrom which the operator could choose. This interface is reflected by thebox 356 outlined in the flowchart 300 which has three paths leading outof the box 357, 358 and 359.

If more measurements in the series of measurements are requested 357,the program loops back to the step where the program accepted the signalfrom the piezoelectric force sensor 324. If more measurements in theseries of measurements are not requested, but instead a new series ofmeasurements are requested, then program either discards or saves into afile the energy data depending upon the discretion of the operator 352before looping back to the step where the program accepted the signalfrom the piezoelectric force sensor 324. If more measurements in theseries of measurements are not requested and no new series ofmeasurements are requested 359, then the program is either discarded orsaved into a file the loss coefficient data depending upon thediscretion of the operator 360 before ending the program 366.

Also, the mechanical energy associated with an impact against a naturaltooth, for example, is primarily dissipated by the periodontal ligament.More specifically, when a tooth is subjected to an impact force, astress wave is transmitted through the tooth and into the periodontalligament, which functions to connect the tooth to the underlying bone.Because of the way it deforms, the periodontal ligament acts as a shockabsorber, dissipating much of the energy associated with the impact.This damping process advantageously reduces the resultant impact forcetransmitted to the surrounding bone. In contrast, dental implantprostheses often have no mechanism by which to dissipate significantamounts of mechanical energy because of the nature of the materialsused. Thus, mechanical energy tends to pass from an implant structure tothe underlying bone with relatively little damping. This difference inmechanical behavior may be particularly critical for people whohabitually brux and/or clench their teeth, since such behavior impartsrelatively large impact forces on teeth. For a physical structure,whether or not a damping material is incorporated into the structure,the mechanical energy associated with an impact against the structuremay generate a different response when there is a crack, microcrack,fracture, microfracture, delamination, defect or any structuralinstability than for a structure without a crack, microcrack, fracture,defect or any structural instability.

The relative extent to which a material dissipates elastic mechanicalenergy can be characterized using the loss coefficient, as discussedpreviously. Loss coefficient values may be determined for any of theobjects mentioned above, including natural teeth, as well as for a widevariety of implant-supported superstructures, such as superstructuresmade of resin matrix composites, gold alloys, porcelain fused to goldlaminates, lithium disilicate, zirconia, all ceramic restorations or anyother material suitable for use in the oral cavity. Implant-supportedstructures typically dissipate less mechanical energy than their naturaltooth counterparts. However, the ability of an implant to dissipatemechanical energy depends on the level of osseointegration around theimplant: poor osseointegration between an implant and the surroundingbone can cause abnormally high levels of energy dissipation. Thus,energy dissipation initially increases after placing an implant, forexample, due to bone remodeling but then usually decreases asosseointegration progresses. Eventually, the energy dissipation(damping) capacity of the implant becomes constant as theosseointegration process progresses to completion. As noted above, fornormal healthy teeth, the percussive energy generated by mastication isattenuated by the periodontal ligament at the healthy bone-natural toothinterface. When a natural tooth is damaged or diseased, an implantreplaces it, but probably and may be definitely, without the ligament asit is generally lost. In most cases, in a successfully integratedimplant, there is no ligament. Under this, the implant may transmit thepercussive forces directly into the bone. To compensate for this loss,the use of, for example, some composites, zirconia and so on, tofabricate the implant abutment has been shown to be effective innumerous studies. The instrument of the present invention may serve inaiding in the construction or fabrication of and/or selection of amaterial for an anatomical structure, for example, an implant. Themeasurement of the dynamic response to load of said abutment materialsmay be used to such purposes and may be useful to predict thesuitability of the restorative material for the implant prior toimplantation or prior to restoration.

Since buccal loading is the more dangerous type of stress encountered,the ability to correlate test results with actual response whenimplanted is another aspect of the present invention. In general,occlusal clenching induces relatively low stresses, working and/ornonworking motion may produce side loading and may induce much higherstresses which may generate highest stress concentration at internalsurface and below the cementum-enamel margin. Thus, quantitativepercussion diagnostics, using the system of the present invention mayaid in selecting the best material or construction design in or for animplant or a natural tooth.

The loss coefficient determination may be performed according to thatdescribed in U.S. Pat. No. 6,120,466, the contents of which are herebyincorporated by reference in its entirety. FIGS. 14 and 15 show formulaeused for calculating loss coefficient and 16 a show an example of a losscoefficient measurement.

Other determinations, such as measuring, for a time interval, energyreflected from the object as a result of the tapping or applying energy,which may include creating a time-energy profile based on the energyreflected from the object during the time interval, and/or evaluatingthe time energy profile to determine the damping capacity of the objectmay be determined, such as disclosed in U.S. Pat. Nos. 6,997,887 and7,008,385, the contents of all of which are hereby incorporated byreference in their entirety.

For example, as illustrated also in FIG. 1, the computer 164 may furtherinclude memory registers, such that time versus percussion response, forexample, the amount of energy reflected from the object 112 at severalpoints over a discrete time period can be recorded. In such embodiments,the energy returned from the object 112 can be plotted as a function oftime on a display attached to the computer 164. This configurationallows the user to view and analyze the time-energy profile of theenergy reflected from the specimen 114.

In addition to generation of a time-energy profile, other analyses canalso be performed on the signals returned from the piezoelectric forcesensor 160 a. For example, the amount of work associated with the impactcan be evaluated by integrating the force applied to the tapping rod 120with respect to the displacement of the specimen. The force applied tothe tapping rod 120 during its impact with the object 112 can bemeasured using the piezoelectric force sensor 160 a. After the impact,the amount of work depends partially on the quantity of defects presentin the object 112. In particular, defects in the object 112 dissipatethe kinetic energy of the rod 120 as it impacts the object 112, therebyreducing the amount of elastic energy available to be returned to thetapping rod 120.

In one embodiment, a comparison of the amount of elastic energy returnedto the tapping rod 120 and the total work associated with the impact canbe used to determine the quantity and nature of structural defectspresent in the object 112. In another embodiment, a Gaussiandistribution peak or other mathematically derived peak, may be fitted tothe measured percussion response such as energy, stress or force data.The residue or mean error may be used to determine how closely themeasured data are representative of a defect-free object 112.

FIG. 16b shows examples of the shape of time versus percussion response,for example, time-energy profiles generated on tooth. For a normaltooth, a smooth, bell-shaped curve is generated, as shown. For anabnormal tooth, a curve having various shapes, for example, asymmetricprofile or multiple peak profile is generated, as shown. Even though theprofiles shown are in reference to tooth, the profiles may begeneralized to any other objects mentioned above, whether anatomical orindustrial or physical.

The device and system of the present invention may also be used in otherdamping factor measurements, such as those disclosed in U.S. Pat. Nos.5,476,009 and 5,614,674; non-invasively determining the loss in densityof a discrete piece of biological tissue, such as that disclosed in U.S.Pat. Nos. 5,836,891, and 5,402,781; a modal damping factor of astructure, such as that disclosed in U.S. Pat. No. 5,652,386; fordetecting an incipient flaw in an object by measurement of the specificdamping capacity of the object, such as disclosed in U.S. Pat. No.4,231,259; non-destructive testing, such as disclosed in U.S. Pat. No.4,519,245; instruments used for causing vibration and analyzed byFourier Transform, as disclosed in U.S. Pat. No. 5,951,292; fordetecting the stability of a tooth in the gum or an implant in the body,as disclosed in U.S. Pat. No. 6,918,763; for determining the mobility ofa tooth or dental implant, such as disclosed in U.S. Pat. No. 5,518,008;or any other measurements using a percussion instrument for generatingvibration in an object; the contents of which are hereby incorporated byreference in their entirety.

The energy application tool 120, for example, a tapping rod 120, mayhave a tip 108 a that may be substantially perpendicular to thelongitudinal axis of the handpiece 104, as shown in FIG. 37 or 37 a. Thetapping rod 120 may be an elongated oscillating lever pivotally seatedat its center of gravity on a pivot axis 18 disposed at substantiallyright angles relative to a longitudinal axis of the housing 132 of thehandpiece 104, and the tip 108 a being at substantially right angles tothe longitudinal axis or oscillating lever 120. The handpiece 104 ofthis embodiment may be adapted for functioning independently of theattitude or inclination of the handpiece 120 with respect to thehorizontal, so that there is no gravity influence if not desired.Moreover, as a result of the angular disposition of the tip 108 a,measurements may be undertaken at locations, which are relativelyinaccessible such as, for example, in the molar area of a patient'steeth.

The tip 108 a may have a circular surface, which strikes against theobject 112 to be tested. The piezoelectric force sensor 160 a may bepositioned at the or relatively close to the tip 108 a so that it isrelatively closer to the object 112 being tested. This has the advantagethat, because greatest movement of the tapping rod 120 occurs at thatlocation and so a smaller detector 160 a may be used.

Well-integrated implants exhibit a low level of energy dissipation witha smooth, symmetric, bell-shaped time-elastic energy profile, as shownin the upper curve of FIG. 16b . As used in this context, the term“elastic energy” refers to the elastic energy imparted to the rod 120 ofthe percussion instrument 100. The elastic energy E_(e) is given byE_(e)=kF², where the constant k varies inversely with the effectiveelastic modulus of the tapping rod 120 and where the force F isproportional to both the mass of the tapping rod 120 and the maximumdeceleration of the tapping rod 120 as a result of the stress wavecreated from the impact.

In contrast to well-integrated implants, implants suffering from poorosseointegration, bone loss, internal defects, or a damaged structuretypically may exhibit a nonuniform time versus percussion responseprofile. For example, FIG. 27 illustrates a “normal” time versuspercussion response profile 200 for a healthy implant, as well as an“abnormal” time versus percussion response profile 210 for an implantstructure that is not well-integrated, as is also shown in FIG. 16b fornormal and abnormal implant. As illustrated, the time versus percussionresponse profile 200 for the healthy tooth has a smooth, symmetric, bellshape, whereas the time versus percussion response profile 210 for theabnormal implant structure is not smooth and symmetric, or may have asecondary maxima 212. The shape of the time versus percussion responseprofile for the abnormal implant structure indicates that defects, suchas loose screws, a damaged internal structure, bone loss at thebone/implant interface, or poor osseointegration, are present. Inaddition to secondary maxima, other abnormalities in the shape of thetime versus percussion response profile that are indicative ofstructural defects include scattered data, asymmetries and irregularshapes.

An additional example of this principle is provided in FIG. 28, whichillustrates a “normal” time versus percussion response profile 300 of awell-integrated implant, as well as an “abnormal” time versus percussionresponse profile 310 for an implant structure that is notwell-integrated. Both of these implant structures are located, forexample, in the mouth of a heavily parafunctional elderly patient. Asexplained previously, the presence of the secondary maxima 312 indicatesthat defects, such as loose screws, a damaged internal structure, boneloss at the bone/implant interface, or poor osseointegration, arepresent at the implant site.

The foregoing examples illustrate that analysis of the time versuspercussion response profile of a dental structure can provideinformation about the integrity and stability of that structure. Theseanalysis techniques provide clinicians with an accurate, fast and simpletool that provides information on the stability of natural andprosthetic dental structures without requiring an invasive procedure.The tab and/or feature add to the repeatability of these measurementsand thus produce smaller standard deviations.

For composite structures, the instrument of the present inventiondescribed above may also be used in fields other than dentistry. Forexample, such instrumentation may be used in assessing the local dampingcapacity of composite structures, such as layered honeycomb compositesor any other structures. In particular, use of such instrumentation inthe testing of composite structures advantageously allows the dampingcapacity of these structures to be evaluated without damaging thestructures. The instrumentation disclosed herein is also light,portable, easy to use, quick and inexpensive as compared to conventionalapparatuses for evaluating damping capacity.

Because damping capacity measures the ability of a material to absorband isolate vibration, damping capacity is of particular interest withrespect to materials used for acoustic insulation, such as in theaerospace, boating, bridges, arch structures, civil engineering andautomotive engineering fields. Thus it is often sought to test thedamping capacity of new materials under development, as well asconventional materials after sustained use.

As an example, layered honeycomb structures generally have a relativelyhigh damping capacity, and thus are often used as acoustic insulators inthese fields. Typical layered honeycomb structures have two relativelythin facings that have high strength and stiffness. The facings enclosea honeycomb core structure that is relatively thick, but lightweight andwith high strength in the direction perpendicular to the facings. Forexample, the honeycomb core structure may include a Nomex® honeycombcore, available from E.I. du Pont de Nemours and Company (Wilmington,Del.). The facings and the core are generally bonded together, eithermechanically or with adhesives (such as, for example, with a phenolicresin or other structural or reactive adhesive), thus giving thestructure composite properties. In the composite structure, the facingsmay carry bending stresses, while the core carries shear stresses. Whenexposed to acoustic vibrations for a prolonged period, degradation inthe bonds between the layers, as well as in the honeycomb core itself,may cause a layered honeycomb core structure to have diminished acousticinsulation capacity.

Referring now to FIG. 29, an exemplary embodiment of an apparatusconfigured for evaluating the damping capacity of composite structuresis illustrated. The apparatus includes an embodiment of the system 100of the present invention mounted within a secured bracket 150 configuredto stabilize the percussion instrument 100. The system 100 mayoptionally be outfitted with a level 152 to assist in aligning theinstrument 100 substantially perpendicular to an object or specimen 112that is to be tested. In an exemplary embodiment, the specimen 112 ismounted in an angle vise 154 having a hand-adjustable vise drive 156,thereby allowing the specimen 112 to be held in compression duringtesting. In a modified embodiment, the angle vise 154 may be outfittedwith rubber grips to reduce external sources of vibrational noise thatcould be detected by the system 100.

Still referring to FIG. 29, the system 100 is electronically connectedto a computer 164 via an instrumentation interface 168. In suchembodiments, the computer 164 may include a display 180 capable ofgraphically presenting data generated by the system 100, such as a timeversus percussion response profile.

The testing apparatus illustrated in FIG. 29 may be used to evaluate thedamping capacity of a wide variety of materials. For example, in oneapplication, this apparatus can be used to evaluate the damping capacityof layered honeycomb composite specimens. In such an application, thespecimen 112 to be tested is mounted in the angle vise 154, which istightened using the vise drive 156 to a torque of approximately 2765gcm, although in other embodiments, the specimen 112 may be loaded to adifferent torque.

In an exemplary embodiment, the instrument of the present invention candetect damping difference between different restorative materials tohelp choose the most biomimetic material to protect the mouth fromdamaging impact, such as normal parafunctional activities, repetitiveloading activity and not limited to just extraordinary events. Inaddition, it can also be employed to evaluate which type ofimplant-supported restoration (for example, CAD/CAM composite resin andzirconia abutments combined with CAD/CAM composite resin and ceramiconlays and crowns) would respond more biomimetically to physiologicallyrelevant dynamic loading, loss coefficient measurements may be employed.After implant/abutment/restoration assembly may be made with a chosenmaterial, the instrument of the present invention may be positionedperpendicularly to the coronal third of the buccal surface of eachrestoration. The tooth may be held at an angle to keep the probehorizontal, as shown in FIG. 26b . The measurements for a chosen objector specimen 112 may be used to predict the most suitable material to beemployed for the implant, restoration, etc. For example, composite resinonlays bonded to zirconia implant abutments may present the mostbiomimetic dynamic response to load when compared to teeth in asimulated bone support structure.

In other exemplary embodiments, the instrument of the present inventionmay also be employed to test the looseness of a tooth structure rightafter dental work or dental implant surgical placement. When a toothstructure is just loose, without defects or cracks as noted above, itmay have a relatively flat time versus percussion response profile, asshown in FIG. 19b, d and f , or FIGS. 20, 20 a-b when they are justloose prior to dental work and following orthodontic movement of theteeth. After allowing time for the dental work to settle and the bone toheal around the new structure and orthodontic positioning of the teeth,a normal bell-shaped profile is shown in FIGS. 20c-e . With anotherexemplary embodiment, the present invention may be used by orthodontiststo measure the stability of teeth after orthodontic movement.

In addition, low or flat profiles with abnormal or multiple peaks, asshown in FIGS. 21b and 22a , may correspond to extreme mobility andstructural breakdown failure, indicating that the tooth may be notrestorable.

In any of the above mentioned measurements, the sleeve 108 of thepresent invention may be fitted to other commercially availablehandpieces that are not adapted for contact with an object undermeasurement, so that the advantages of the present invention may also berealized. Any suitable manner of attachment of the sleeve 108 to theavailable handpieces may be used to modify the handpieces.

As noted, in some embodiments, the sleeve 108 and/or portions of thehousing 132 may include coatings capable of eliminating, preventing,retarding or minimizing the growth of microbes, thus minimizing the useof high temperature autoclaving process or harsh chemicals and mayincrease the kind and number of materials useful as substrates formaking such tools or instruments.

The coatings may include chemical anti-microbial materials or compoundsthat are capable of being substantially permanently bonded, at least fora period such as the useful life sleeve 108, or maintain theiranti-microbial effects when coated with the aid of coating agents, ontothe exposed surfaces of the sleeve 108. In one example, the chemicalsmay be deposited on the surface of the sleeve 108 by covalent linkage orlinkages.

In other embodiments, the coatings may include chemical antimicrobialmaterials or compounds that may be deposited in a non-permanent mannersuch that they may dissolve, leach or otherwise deliver antimicrobialsubstances to a useful field, such as the mouth, during use.

In still other embodiments, the coatings may include sources ofanti-microbial agents that may leach and/or release agents in a moistenvironment or upon contact with moisture. These sources may beincorporated into the substrate materials used for manufacturing thesleeve, or included in the coatings coated on the exposed surfaces ofthe sleeve 108. Incorporation of the sources is especially suited topolymeric substrates.

Chemical antimicrobial materials or compounds may include a variety ofsubstances including, but not limited to antibiotics, antimycotics,general antimicrobial agents, metal ion generating materials, or anyother materials capable of generating an antimicrobial effect. Chemicalantimicrobial materials or compounds may also be selected to, forexample, minimize any adverse effects or discomfort to the patient.

The anti-microbial compound may include, but are not limited to,antibiotics, quaternary ammonium cations, a source of metal ions,triclosan, chlorhexidine, and/or any other appropriate compound ormixtures thereof.

In yet further embodiments, antimicrobial activity may be achieved byutilizing the antimicrobial properties of various metals, especiallytransition metals which have little to no effect on humans. Examples mayinclude sources of free silver ions, which are noted for theirantimicrobial effects and few biological effects on humans. Metal ionantimicrobial activity may be created by a variety of methods that mayinclude, for example, mixing a source of a metal ion with the materialof a dental instrument during manufacture, coating the surface bymethods such as plasma deposition, loosely complexing the metal ionsource by disrupting the surface of the dental instrument to formaffinity or binding sites by methods such as etching or coronaldischarge, and depositing a metal onto the surface by means such aselectroplating, photoreduction and precipitation. The sleeve 108 surfacemay then slowly release free metal ions during use that may produce anantimicrobial effect.

In some embodiments, the source of metal ions may be an ion exchangeresin. Ion exchange resins are substances that carry ions in bindingsites on the surfaces of the material. Ion exchange resins may beimpregnated with particular ion species for which it has a givenaffinity. The ion exchange resin may be placed in an environmentcontaining different ion species for which it has a generally higheraffinity, causing the impregnated ions to leach into the environment,being replaced by the ion species originally present in the environment.

In one embodiment, a sleeve may include an ion exchange resin containinga metal ion source, such as, for example, silver. Ion exchange resinscontaining metal ion sources may include, for example, Alphasan®(Milliken Chemical), which is a zirconium phosphate-based ceramic ionexchange resin containing silver. An ion exchange resin may be coatedonto the sleeve 108 or it may be incorporated into the material of thesleeve 108.

In yet another embodiment, the sleeve 108 may be made from natural plantmaterials, natural material coating or blends thereof, having inherentantimicrobial effects. Such materials include materials like bamboo,believes to possess antimicrobial activity due to some novelchitin-binding peptides.

The present invention also provides a system and method for measuringstructural characteristics mentioned above using an energy applicationtool such as a tapping rod and includes disposable features for aidingin eliminating or minimizing contamination of the object undergoing themeasurement through transfer from the system or cross-contamination fromprevious objects undergoing the measurements, without interfering withthe measurement or the capability of the system. The system may or maynot include a feature for aiding repositionability.

In one embodiment of the invention, a disposable feature may include aseparable and disposable tip 108 a of the energy application tool 120,such as a tapping rod 120. The tip 108 a may be connected to the rest ofthe tapping rod via a magnet 801 or magnetic element 801. In one aspect,the magnet or magnetic element 801 may be present on tip 108 a and thusis also disposable. In another aspect, the tip 108 a may be connected tothe rest of the tapping rod via a magnet or magnetic element present onthe front end 120 a.

In another embodiment of the invention, the disposable feature mayinclude a disposable membrane 800 and a disposable, separable tip 108 a,the disposable membrane 800 not covering the tip 108 a so that membraneremains intact thru the extension of the energy application tool 120, orthru the oscillation of the energy application tool 120 about a pivotpoint, as described above, during measurement.

In one aspect, the separable tip 108 a is shown in FIG. 30 without anyfeatures for aiding in repositionability, for example, a sleeve 108and/tab 110. The tip 108 a also extends from the end of the disposablemembrane 800 but retains to it in a press fit with a small collar 80 b.A cross-sectional view of the front-end 120 a of an embodiment of theenergy application tool 120, for example, a tapping rod 120, is shown.The tip 108 a is attached to the front portion 120 a of the tapping rod120 magnetically. The tip 108 a has an object 112 contacting surface 120c, as shown in FIG. 30a . In one embodiment, the tip 108 a includes amagnet or magnetic element 801, not specifically shown here. In anotherembodiment, the front portion 120 a of tapping rod 120 includes a magnetor magnetic element 801 or 80 a, as shown in FIG. 36d . The membrane 800is retained by a retaining collar 80 b and covers the front portion 120a, but leaving the tip 108 a exposed, as shown in FIGS. 30, 30 a, 30 band 36 c. FIGS. 30a and 30b show the rear view and front view of tip 108a of FIG. 30, respectively, with the retaining magnet 801 or magneticelement 801. As shown herein, the membrane does not cover the tip 108 aand the tip 108 a and membrane 800 are both disposable. In otherembodiments, the membrane 800 may cover the tip 108 a as well, such asmembrane 800 having folds 800 b, as shown in FIG. 33, or the tip 108 amay be perpendicular to the rest of the tapping rod 120, and thus thetip 108 a may be reusable.

A sleeve is not present in the embodiment of FIG. 30 and thus thehousing 132 of the handpiece 104 enclosing the tapping rod 120 does notcome into contact with an object 112 undergoing measurement, thuswithout providing an aid on repositionability. The front end 120 c ofthe tip 108 a comes into direct contact with the testing surface, suchas a tooth 112.

In another aspect, a separable tip 108 a as shown in FIG. 31 havingfeatures for aiding in repositionability, for example, a sleeve 108.FIG. 31 shows a cross-sectional view of the front end 120 a of energyapplication tool 120 of the present invention with a separable tip 108a, membrane 800 and sleeve 108 along with a sleeve attachment location109 b along the outside part of the handpiece 104. The tip 108 a extendsfrom the end of the disposable membrane 800 but retains to it in a pressfit with a small collar 80 b or 80 b-1, as shown in FIG. 36c . Retainingcollar 80 b may be used securing membrane 800 to the sleeve 108 andretaining collar 80 b-1 may be used for securing the tip 108 a to themembrane 800, as shown in FIG. 36c . FIG. 31 also shows a feature 109 a,for example, a dent, a channel, a depression or similar towards themid-section of the front part 104 a for attaching the sleeve 108 ontothe handpiece 104. This feature may be mated with either a ridge, a bumpor similar in the handpiece, not specifically shown here, for effectingsuch attachment. There may also be other features for further securingthe sleeve 108 to the housing 132, for example, a guide clip 109 b, asshown in FIGS. 31 and 32. According to one aspect, a portion of thesleeve 108 may also be exposed. The exposed portion 108 b is separablefrom the rest of the sleeve 108, as shown in FIG. 36, except without thetab 110, so that only the exposed part 108 b is disposable. According toanother aspect, the entire sleeve 108 may be exposed, as shown in FIGS.34b 1 and 2, except without the tab 110, and the entire sleeve 108 isdisposable.

In a further aspect, a separable tip 108 a as shown in FIG. 31 or 32,having features for aiding in repositionability, for example, a sleeve108 and a tab 110, as shown in FIG. 32. FIG. 32 shows a cross-sectionalview of the front end 120 a of energy application tool 120 of thepresent invention with a separable tip 108 a, membrane 800 and sleeve108 with tab 110 with a sleeve attachment location 108 c along the outerpart of the handpiece 104. The tip 108 a extends from the end of thedisposable membrane 800 but retains to it in a press fit with a smallcollar 80 b. FIG. 31 also shows a feature 109 a, for example, a dent, achannel, a depression or similar towards the mid-section of the frontpart 104 a for attaching the sleeve 108 onto the handpiece 104. Thisfeature may be mated with either a ridge, a bump or similar in thesleeve 108, not specifically shown here, for effecting such attachment.According to one aspect, a portion 108 b of the sleeve 108 may also beexposed. The exposed portion 108 b may be separable from the rest of thesleeve 108, as shown in FIG. 36, so that only the exposed part 108 b isdisposable. According to another aspect, the entire sleeve may beexposed, as shown in FIGS. 34b 1 and 2, and the entire sleeve 108 isdisposable. The energy application tool assembly may be encased orenclosed in a housing 109, as shown in FIGS. 31 and 32, which fit insidethe handpiece housing 132.

In yet a further aspect, a sleeve 108, tab 110 and feature 111, asdescribed above, may also be present for aiding in repositionability andare also disposable.

In a still further embodiment of the invention, a disposable feature mayinclude a disposable membrane 800 that covers or envelopes the tip 108 aof the front portion 120 a of the energy application tool 120.

In one embodiment, the energy application tool 120 has a disposablemembrane 800 surrounding tip 108 a, as shown in FIG. 33. The membrane800 may be folded or fluted on both side of the housing 104 around thetip 108 a so that when the energy application tool is in the extendedposition, the folds 800 b or flutes 800 b become unfolded to protect thetip 108 a from contamination, and without tearing or ripping themembrane 800. In one aspect, the application tool 120 may have a frontportion 120 a having a slight neck portion, not specifically shown,towards the tip 108 a for location of a collar 80 b for retaining themembrane 800. In another aspect, the application tool 120 may have afront portion 120 a having a separable tip 108 a for location of acollar 80 b for retaining the membrane 800 about the separation point.

In another embodiment, the energy application tool 120 is as shown inFIGS. 37 and 37 a. The disposable feature may include a disposablemembrane 800 surrounding tip 108 a, as shown in FIG. 37 b.

Referring to FIGS. 37, 37 a, and 37 b, a tip portion 108 a may strike atest object 112 at a constant velocity when the energy application tool120 is a tapping rod 120. The tapping rod 120 may be an elongatedoscillating lever pivotally seated at its center of gravity on a pivotaxis 18 disposed at right angles relative to a longitudinal axis of thehousing 132 of the handpiece 104, and the tip 108 a being atsubstantially right angles to the longitudinal axis of the housing oroscillating lever at rest 120. The tapping rod 120 may thus rock backand forth on the pivot axis 18, such as from a substantially parallelorientation to the longitudinal axis of the housing 132 to an acuteangle orientation, to generate the oscillatory movement up and down ofthe tip 108 a. The membrane 800 is retained by a collar 80 b, as shownin FIG. 37b , and the tip 108 a is not exposed to the test object 112.The handpiece 104 of this embodiment may be held at other than ahorizontal position parallel to the longitudinal axis of the housing 104and is thus amenable to be functioning independently of the attitude orinclination of the handpiece 120 with respect to the horizontal, andthere is no gravity influence if not desired. Moreover, because of theangular disposition of the tip 108 a, measurements may be undertaken atlocations which are relatively inaccessible such as, for example, in themolar area of a patient's teeth, as mentioned before. The tip 108 a mayhave a circular surface which may strike against the object 112 to betested. The piezoelectric force sensor 160 a may be positioned at the orrelatively close to the tip 108 a so that it is relatively closer to theobject 112 being tested. This has the advantage that, because greatestmovement of the tapping rod 120 occurs at that location and thus asmaller detector 160 a may be used, as mentioned before. In one aspect,the handpiece may not have a sleeve 108, as shown in FIGS. 37, 37 a and37 b. In another aspect, the handpiece may have a sleeve 108, though notspecifically shown in FIGS. 37, 37 a and 37 b. In a further aspect, thehandpiece may have a sleeve 108 and a tab 110 and/or feature 111, thoughnot specifically shown in FIGS. 37, 37 a and 37 b.

FIG. 34 shows a cross-sectional view of a handpiece 104 of the presentinvention having the front end of the energy application tool 120 ofFIG. 32, with the object 112 contacting surface 120 c being exposed. Inone aspect, the sleeve 108 may also have a front end 108 b that isseparable form the rest of the sleeve 108, as shown in FIGS. 34, 34 a,b, b 1, c, and d, and 35 a. This separable part 108 b may be the onlypart of the sleeve 108 that is disposable when separated. In anotherembodiment, the entire sleeve 108 may be disposable. If the entiresleeve is disposable, the membrane 800 may cover the handpiece away fromthe sleeve 108 or including the sleeve 108 for extra protection.

The disposable membrane 800 of any of the above embodiments may beattached to the sleeve 108 in a number of ways. In one embodiment, thedisposable membrane may be retained to the sleeve 108 by ultrasonicbonding. In another embodiment, the disposable membrane may be retainedto the sleeve 108 thru heat sealing. In a further embodiment, thedisposable membrane may be retained to the sleeve 108 by over molding.

FIGS. 34a, 34b 1, b 2, 34 c, 36 c and 36 d show the exploded views ofthe various parts of the handpiece 104 of FIG. 34. FIG. 34a shows theexploded view of the entire handpiece 104 of FIG. 34. The handpieceincludes an upper cover 132 a and bottom cover 132 b, as shown in FIG.34a . A light, for example, an status LED 90 below the cover 132 a maybe present to indicate the on and off of the handpiece 104 and acorresponding LED light pipe 90 a located on the top cover 132 a towardsthe front end 104 a, as shown in FIG. 34a , for transmitting light tothe surface. The handpiece 104 may also include a switch 124, which maybe a rocker switch or a push button. The switch may also be activated bya foot switch connected thru wired ore wirelessly, or the switch may beactivated remotely or wirelessly. The operative parts of the switch 124may be located on a PCBA 130 (printed circuit board). The housing 132may also include a cap 132 c for closing the end of the housing awayfrom the tapping rod 120 as well as an exterior cover 132 d for coveringthe entire housing 132 which may provide a grip portion for theoperator. In one aspect, the handpiece may be tethered to an externalpower supply, as shown in FIG. 1, or be powered by an electrical sourceincluded inside the housing, such as, for example, a battery 131, asshown in FIG. 34a , a capacitor, a transducer, a solar cell, an externalsource and/or any other appropriate source.

FIGS. 34b, 34b 1 and 36 c show the exploded view of the front end FIG.34a . FIG. 34b shows a separable front portion of the sleeve 108 b, andrear portion 108 not surrounded by a disposable membrane 800. FIGS. 34b1 and 36 c show the rest of the sleeve 108 having a membrane 800covering it with the separable front portion 108 b being exposed. FIG.34c shows the top view of FIG. 34 without the top cover 132 a, thusshowing all the parts indicated also in FIG. 34a , including the zoomedin view of the front end of the tapping rod 120, with the sleeve 108,the tab 110, the tip 108 a and front end 108 b of the sleeve 108 whichmay come into contact with the surface of the object undergoingmeasurement.

In one embodiment, as noted above, the handpiece 104 may be powered bybatteries 131, as shown in FIG. 34a . In another embodiment, thehandpiece 104 may be tethered to a power source, as shown in FIG. 1.

The sleeve 108 may include a sleeve grip 104 e and an end cap 104 f, asshown in FIG. 34 b.

FIGS. 35 a, b and c shows the handpiece of FIG. 34 in various views,showing all the outer components of the handpiece 104 from differentangles, fully assembled.

FIGS. 36, a, b, c, and d show the detailed views of FIG. 34. FIGS. 36aand b show the sleeve 108 fitted over the tapping rod 120 in a top viewand side view without housing for energy application tool 120 or housing132.

FIG. 36d shows an exploded view of the complete handpiece in more detailthan FIG. 34a . As described in FIGS. 1 and 5 above, the energyapplication tool 120, such as a tapping rod 120, may be encased orenclosed in its own housing, with the front portion 120 e and the rearportion 120 f, as shown in FIGS. 36a and 36d , which are then enclosedinside the housing 132. A magnet or magnetic element 80 a insures thatthe tip 108 a remains in contact with the rest of the tapping rod 120. Asensor 160 a, which may include a piezo chip, a pin 160 c and anadjustable holder for preloading the chip. The chip may generate voltagewhen struck by the tapping rod 120 and the pin 160 c provides electricalcontact between the chip and the rest of the sensor 160 a.

The components of the tapping rod 120 may be secured in place in variousways, for example, with a screw 160 e. Referring again to FIGS. 36a, 36band 36d , the rear housing 120 f houses the primary components of thetapping rod 120, including a coil 160 f surrounding it which may carrysignal from the pin 160 c. A pair set screw 160 g may be located towardsthe end of the rear housing 120 f for adjusting or limiting the strokesof the tapping rod 120, for example, the number of strokes. As mentionedabove, an electro-magnetic coil 156 may be employed to propel thetapping rod when it is energized. To assist the return or contraction ofthe tapping rod, a device 156 a such as a propulsion magnet may beemployed. A device 156 b, such as an iron core may assist in both thepropulsion and return of the tapping rod 120.

As mentioned above, the system and method of the present invention isnon-destructive. This is applicable to a system that may or may not havedisposable parts and/or features for aiding in repositionability. Thepresent invention further relates to a system and method for measuringstructural characteristics that minimizes impact, even the minute impacton the object undergoing measurement, without compromising thesensitivity of the measurement or operation of the system. In oneembodiment of the invention, the system includes an energy applicationtool 120 that is light weight and/or capable of moving at a slowervelocity such that it minimizes the force of impact on the object 112during measurement while exhibits or maintains better sensitivity ofmeasurement. In one embodiment, the energy application tool 120, forexample, the tapping rod 120, may be made of lighter material tominimize the weight of the handpiece 104. The lighter tapping rod 120may also reduce the impact force on the object 112 during measurement.The housing 120 e and f enclosing the tapping rod 120 may also be madeof a lighter material, though this will only helps to minimize theoverall weight of the handpiece 104 and does not have any effect on theoperation of the handpiece 104. In another embodiment, the energyapplication tool 120, for example, the tapping rod 120, may be madeshorter and/or of smaller diameter such that the size of the handpiece104 is minimized as well as the impact force on the object 112 duringmeasurement. This may or may not also be in combination with the housing120 e and f enclosing the tapping rod 120 being made of a lightermaterial. In a further embodiment, the system may include a drivemechanism 160 that may lessen the acceleration of the energy applicationtool 120. For example, the drive mechanism 160 may include a smallerdrive coil 160 a to lessen the acceleration of the energy applicationtool 120, and the impact force on the object 112 during operation whilemaintaining sensitivity of measurement, whether or not it is lightweight, and/or smaller in length or diameter, or housing 120 e 2 and fenclosing the tapping rod 120 being made of a lighter material. Theseembodiments may also be combined with any of the above embodiments forfurther advantages.

The speed of conducting measurement may also be desirable withoutincreasing the initial velocity of impact so as to minimize impact onthe object 112 during measurement. The present invention relates to yetanother system and method for measuring structural characteristicshaving a drive mechanism 160 that may decrease the travel distance ofthe energy application tool 120, for example, from about 4 mm to about 2mm, while maintaining the same initial velocity at contact and thus,faster measurement is possible without compromising the operation of thesystem. The system may or may not have disposable parts and/or featuresfor aiding in repositionability and/or lessening impact with featuresmentioned before, or including the other embodiments on reducing impactforce on the object 112 by the energy application tool 120. Thisembodiment may also be combined with any of the above embodiments forfurther advantage, whether or not it is light weight, and/or smaller inlength or diameter, or housing 120 f enclosing the tapping rod 120 beingmade of a lighter material.

As mentioned above, during measurement, the handpiece 104 may contactthe object 112 with the end of the sleeve 108. The contact pressure mayvary depending on the operator. It is desirable that the pressure beconsistently applied in a certain range and that range not be excessive.A force sensor may be included in the handpiece 104 for sensing thispressure application and may be accompanied by visual signal, voice ordigital readout. This sensor may be employed also for assuring thatproper alignment against the object during measurement is obtained. Thesensor may include strain gauges or piezoelectric elements.

In some embodiments, multiple strain gauges mounted to a single or toseparate cantilevers may be utilized. The cantilever(s) may also, forexample, be present on a separate component from the rest of thehandpiece 104 or sleeve 108, such as, for example, on a mounting device.A mounting device may be utilized to mount strain gauges or other forcemeasuring elements between the sleeve and the handpiece, such as, forexample, the mounting device 900, shown in the top view of FIG. 38. Themounting device 900 may generally include a central channel 901 in mainbody 906, through which the tip, such as tip 108 a (not shown), may passthrough into a sleeve, such as sleeve 108 (not shown). The mountingdevice 900 may, for utilization with strain gauges, include at least onecantilever arm, such as the cantilever arms 902, which may generallypivot or flex at a connection with the main body 906, such as atconnections 904, such that the cantilever arms 902 may be deformed ordeflected away (such as direction A) from the main plane B of the mainbody 906 by the application of a force normal (direction A) to thesurface of the cantilever arms 902, as illustrated in the side view ofthe mounting device 900 in FIG. 38a . Strain gauges, such as the gauges910, may generally be mounted on the cantilever arms 902 such that theymay measure the deformation or deflection of the cantilever arms 902 ator near the connections 904.

In some embodiments, such as illustrated in FIG. 38, the mounting device900 may be a separate component and may further include securingfeatures, such as through-holes 903 in main body 906. The through-holes903 may generally be utilized by passing securing bolts (not shown) orother fasteners through them, such as to a handpiece, sleeve, or both.In other embodiments, the mounting device 900 may be an integral portionof a handpiece, a sleeve, or both.

The mounting device 900 may also include multiple cantilever arms 902and strain gauges 910, as illustrated in FIG. 38. For example, threeseparate cantilever arms 902 may be attached to the main body 906, suchas, for further example, separated by 120° about the main body 906, asillustrated. In general, multiple cantilever arms 902 and strain gauges910 may be utilized, for example, to normalize the measurement ofdeformation and subsequently the force measured.

In one aspect, the force measurement may be connected to a visualoutput, such as lights. The lights, either singly or multiply, may bepositioned in any convenient location on the handpiece 104 to be easilyseen by the operator performing the measurement. In one embodiment, amultiple light system may be included. For example, a green light mayindicate the right amount of force while a red light may indicate toomuch force. In another embodiment, a one light system may be included.For example, no light may give a signal of right amount of force and ared light may give a signal of too much force. In a further embodiment,a flashing red light may indicate too much force.

In another aspect, the force measurement may be connected to an audibleoutput. The audible mechanism may be located either on the handpiece 104or the rest of the system of which the handpiece 104 is a part. In oneembodiment, the audible output may include a beeping sound to indicatetoo much force. In another embodiment, the audible output may include abeeping sound with a flashing red light to indicate too much force. In afurther embodiment, the force measurement may be connected to a voicealert system for alerting too much force. In yet a further embodiment,the force measurement may be connected to a voice alert system and aflashing red light for alerting too much force.

EXAMPLES Example 1: In Vitro Studies of Bone Density

Implants used for this study were four threaded titanium implantgeometries from:

1 and 2. Nobel Biocare (TiO2 coated, 13 mm long): Branemark Mark IV(max. diameter 4 mm); Replace selected tapered (max. diameter 4.3 mm);

3 and 4. Dentsply (13 mm long, 5.5 mm max. diameter); Frialit-2 (steppeddesign; XIVE (designed for immediate loading).

Procedures:

2.5×2.5×4 cm foam blocks were fabricated. The implants were “surgically”placed by the manufacturers. Holes were manually drilled in thesimulated bone block, then the implants were placed with a torquewrench. Testing abutments were attached to the implants and the blocksplaced in a vise with consistent mounting displacement. Threemeasurements (30 percussions) were performed for each specimen.Results of the testing are shown in FIGS. 10 and 10 a for 1 and 2; and11 and 11 a for 3 and 4. These samples would have produced similargraphs, adjusting for slight differences in the materials themselves.However, the graphs showed differences, even though the objects wereidentically prepared, but with different operators or same operatorusing slight variation in technique, for example, different sized-holesmight have been drilled for mounting the object. These differences werepicked up by the instrument, showing in the difference in graphs,showing that differences in the surrounding environment were revealed bythe instrument of the present invention.

Example 2: Evaluation of the Importance of Buccal Percussion Loading

Buccal loading, as mentioned above, is typically the more dangerousdieection of loading. In general, occlusal loading induces relativelylow stresses. The working and/or nonworking motion produces side loadingand induces much higher stresses that may generate a high stressconcentration at external and internal surfaces and below margin. Thus,an embodiment of the present invention was used to perform the testbelow.

Procedure:

-   -   Using the system of the present invention, with loadings such as        that shown in FIG. 12, measurements were made. The instrument        loading of a maximum force of 1-15 Newtons were used in general,        with maximum loadings chosen depending on the object or        specimen. The tapping rod was free-floating. The kinetic energy        was controlled. The impact velocity was 60 mm per second.

The instrument of the present invention was placed upon the object, asdepicted in FIG. 26b . Using the calculations depicted in the FIG. 13,the tapping rod had a mass of 8 grams. The input energy, U was 0.5 mv2,i.e., the kinetic energy of the tapping rod. The maximum force (F) wasused to determine the energy dissipated (D). Deceleration, a, wasmeasured and the return energy, ER=U−D was calculated. The dynamicresponse measured after impact of the object with the instrument of thepresent invention was made and depicted in FIG. 16. Loss coefficientsand energy return versus percussion response graphs were produced usingthe equations depicted in FIGS. 14 and 15. The resultant graphs, asshown in FIG. 16b , depicted what is normal and abnormal. For normalstructure, a smooth, almost bell-shaped graph was obtained. For anabnormal structure, which could have any of the defects or cracks, asnoted previously, an irregular graph was generated.

Example 3: Finite Element Analysis

This analysis method involved the use of numerical models to simulateactual testing using the system and method of the present invention.

Layered structures were used in the present experiment, one structurewith no defect in the laminated composite layer (FIG. 24) and one with adefect in the center of the composite laminated layer (FIG. 24b )

FIG. 23 measured the residence time of the tapping rod against anobject. A glass rod or cylinder was used to simulate a tooth structurefor the measurement shown in FIG. 23. The graph in FIG. 23 showed therelative positions of the tapping rod and glass rod with time. Whentapping rod tapped the surface of the glass rod, their respectivepositions coincided at the start. As time progressed, the tapping rodgradually moved away from the surface of the glass rod and at 250 μsec.,they separated, indicating the residence time of the tapping rod on thesurface to be 250 μsec.

Using this residence time, analysis on the composite plates of FIGS. 24and 24 b were made. Results are shown in FIGS. 24a and 24c ,respectively. The graph in FIG. 24c confirmed the defect in thecomposite layers, a delamination of the layers in the compositestructure. A repeat measurement was made and the results are shown inFIGS. 25 and 25 a. Thus, the analysis maybe used to simulate the systemand method of the present invention.

Example 4: To Evaluate Loss Coefficient for Determining the MoreBiomemetically Compatible Material to Use in Implants, Restorations, Etc

To evaluate the LC of extracted human teeth and assess which type ofimplant-supported restoration (CAD/CAM composite resin and zirconiaabutments combined with CAD/CAM composite resin and ceramic onlays andcrowns) would respond more biomimetically to physiologically relevantdynamic loading, the instrument of the present invention, as shown inFIG. 27b was used to measure the loss coefficient (LC) of somematerials. More suitable materials generated bell-shaped graphs similarto the upper graph of FIG. 16b , while less suitable materials generatedirregular graphs similar to that of the lower graph of FIG. 16b ordemonstrated a LC value that was much lower than that found in a naturaltooth, thus facilitating the choice of materials prior to restorationwithout having to rely on trial and error, which can be time consumingand expensive if re-treatment is indicated, while exposing patients todiscomfort and potential danger of receiving more damage.

Example 5: Sensitivity and Accuracy of the Instrument of the PresentInvention to Measure Cracks, Defects, Etc

Actual human teeth inside the mouth of a patient were used in thisstudy. The information of FIGS. 17 and 17 a-h were generated on the sametooth. FIGS. 17 and 17 a showed radiographs of a patient's tooth showingno pathology. FIG. 17b shows an image of an older alloy restoration alsoshowing no pathology. Thus the radiographs and visual inspection bothshowed that the tooth was normal, i.e., no defects or cracks. Based onthese usual testing methods, a symmetrical or bell-shape time versuspercussion response profile or graph would be expected (or one similarto the light shade curve in FIG. 17c , calculated based on the formulaein FIGS. 13, 14 and 15).

However, on the same day, a time versus percussion response graph wasmade using the instrument of the present invention as shown in FIGS. 1and 16, using the sleeve with a tab, as shown in FIG. 27d . FIG. 17cshowed the same tooth as in FIGS. 17 and 17 a, showing an abnormal timeversus energy return percussion response graph indicating someabnormality. The abnormal graph indicated that the tooth had cracks atdifferent places within the structure of the old filling, as indicatedby the arrows in FIG. 17c , with an asymmetrical or non-bell-shapedcurve. Numerous measurements were performed and these all showed thesame irregular shape, as well as reproducibility of the measurements.Thus, the instrument of the present invention was capable of detectingany abnormality. The abnormal secondary peaks were indicated by arrowsin the FIG. 17f also, showing cracks.

FIG. 17d showed an image of the same tooth as FIG. 17 during removal ofthe older alloy filling, showing a significant crack in the alloyfilling, which had developed microleakage and gross decay underneath thefilling. The fractured alloy filling was leaking and allowing decay todevelop under the old filling. This confirmed the abnormality detectedby the instrument of the present invention.

FIGS. 17e and 17f showed the same pre-treatment time versus percussionresponse graph prior to the alloy removal. Rechecked showed that thecrack measurements were reproducible, as shown in FIGS. 17e -f.

FIG. 17 g showed the time versus percussion response graph taken thesame day as FIG. 17e after the old alloy and decay were removed and anew well-sealed composite restoration was placed. The time versuspercussion response graph of the tooth was normal again.

FIG. 17h shows the new composite restoration that tested normal in FIG.17g after the older alloy restoration was replaced earlier in the day.FIGs. The drama of this example was that the energy return profile of 17f and 17 g were for the same tooth on the same day, the difference beingthat the old filling and decay was removed and a fresh bonded compositerestoration was placed, which was the photo 17 h.

This experiment was repeated with another tooth. The results are shownin FIGS. 18, 18 a-f. FIG. 18 showed a tooth with no pathology shown on aradiograph. FIG. 18a showed an abnormal time versus percussion responsegraph for the tooth shown in FIG. 18 radiograph. FIG. 18b is aphotograph of the tooth evaluated in FIGS. 18 and 18 a showing nosignificant pathology upon visual inspection. However, upon removal ofthe filling, deep decay was present and microleakage under the oldfilling. FIGS. 18c and 18d and the same graph repeated showing thedefect prior to removal of the old alloy. FIG. 18e shows a normal ERGfor the same tooth after the final restoration was completed. FIG. 18fshowed the same tooth shown in 18 b with the new restoration that wastesting normally. This again indicated the accuracy of the instrument ofthe present invention.

In addition, as mentioned above, the system of the present invention mayalso be used to detect looseness of a tooth structure right after dentalwork. FIGS. 19-19 g show pre-treatment radiographs and time versuspercussion response graphs for three different upper anterior teeth.

FIGS. 19, 19 a, c, e and g showed minor old dental work, i.e., the whitespots represented fillings and the large white spot was a porcelainfused to gold crown. The graphs produced with an embodiment of theinstrument of the present invention was normal, i.e. Symmetrical, butlow, as shown in FIG. 19b, d and f , and FIG. 20. The tooth was looseand not stable due to the patient recently completing orthodonticmovement of his teeth, though structurally sound.

FIGS. 20, 20 a and 20 b also showed the time versus energy returnpercussion response curves of teeth that were loose prior to treatment.FIGS. 20c, 20d, 20e were the post restoration time versus percussionresponse graphs for the same teeth. FIG. 20f showed the final photo ofthe restored and structurally normal teeth. The graphs were higher herebecause the teeth were more stable in the bone after treatment. The bonehad been able to remodel post orthodontic treatment and the teeth werestructurally strong. Thus, after allowing time for the dental work tosettle and the tooth structure more firmly attached, a normalbell-shaped profile resulted with higher profiles indicating more toothstability (less tooth mobility due to normal bone maturation).

On the other hand, when low or flat profiles with abnormal or multiplepeaks, as shown in FIGS. 21b and 22a , were produced, extreme mobilityand structural breakdown failure were indicative of the fact that thetooth was not restorable. FIGS. 21 and 21 a were x-rays of the toothused in FIG. 21b , showing multiple fillings and FIG. 22 showed the deepgross decay under this old crown, deep into the root structure that thistooth needed an extraction due to extensive terminal decay. FIG. 22ashowed the time energy profile made using the system of the presentinvention of the same tooth, showing an extreme abnormality in shape andheight.

Having described the invention by the description and illustrationsabove, it should be understood that these are exemplary of the inventionand are not to be considered as limiting. Accordingly, the invention isnot to be considered as limited by the foregoing description, butincludes any equivalents.

The invention claimed is:
 1. A device for determining structuralcharacteristics of an object, comprising: a housing having an open endand a longitudinal axis; an energy application tool mounted inside saidhousing for movement, said energy application tool having a restingconfiguration and an active configuration, said active configurationbeing an extended form of said resting configuration; a sleeveprotruding from said open end of said housing for a distance, saidsleeve being adapted for resting directly against said object with atleast a resting portion of said open end; a drive mechanism supportedinside said housing, said drive mechanism being adapted for moving saidenergy application tool between said resting and active configurations;and a sensor located inside said housing adapted for sensing an amountof a contact force when said sleeve rests on said object, said energyapplication tool passing through said sensor.
 2. The device of claim 1wherein said energy application tool comprises a separable tip connectedto a front portion of said energy application tool by magnetic force. 3.The device of claim 2 wherein said tip comprises a magnet or a magneticelement for attaching it to said front end of said energy applicationtool.
 4. The device of claim 1 further comprising a disposable featureadapted for enveloping a portion of said device.
 5. The device of claim4 wherein said disposable feature comprises a membrane covering-saidenergy application tool, said membrane comprising a retractedconfiguration and an extended configuration adapted for accommodatingsaid resting and active configurations of said energy application toolduring measurement.
 6. The device of claim 5 wherein said membranecomprises folds or flutes.
 7. The device of claim 5 wherein saiddisposable feature comprises said sleeve and a separable tip extendingfrom an exposed end of said membrane and retained to said membrane usinga collar.
 8. The device of claim 4 wherein said disposable featureadapted for allowing movement of said energy application tool betweensaid resting and said active configurations.
 9. The device of claim 8wherein said disposable features comprises a separable tip, said sleeveand a tab extending from said sleeve perpendicular to said restingportion of said open end of said sleeve.
 10. A system for determiningstructural characteristics of an object, comprising: a device having ahousing with an open end and a longitudinal axis; an energy applicationtool mounted inside said housing for applying energy to said object,said energy application tool having an active form and a resting form,said active form is an extended form of said resting form; a drivemechanism supported inside said housing, said drive mechanism adaptedfor moving said energy application tool; a sleeve protruding from saidopen end of said housing for a distance, said sleeve being adapted forresting directly against said object with at least a portion of saidopen end; a sensor positioned inside said housing adapted for monitoringan amount of a force between said sleeve and object when said sleeverests on the object, said energy application tool passing through saidsensor; and a disposable feature for enveloping at least a portion ofsaid device, said disposable feature having a retracted form and anextended form adapted for accommodating the resting and active forms ofthe energy application tool during a measurement.
 11. The system ofclaim 10 further comprising a computer coupled to said device adaptedfor determining structural characteristics of said object.
 12. Thesystem of claim 10 wherein said sensor comprises at least one straingauge mounted to at least one cantilever within said housing.
 13. Thesystem of claim 10 wherein said sensor comprises at least onepiezoelectric element.
 14. The system of claim 10 wherein said energyapplication tool having a front portion that is substantiallyperpendicular to the longitudinal axis of the housing and said tooloscillates from a substantially parallel position to the housing to aposition at an acute angle with the housing about a pivot point.
 15. Thesystem of claim 10 further comprising a tab extending from the sleeve ina direction perpendicular to the resting portion of the open end of thesleeve.
 16. A system for determining structural characteristics of anobject, comprising: a device having a housing with an open end at itsfront portion and a longitudinal axis; an energy application toolmounted inside the housing for movement between an active form and aresting form; a sleeve protruding from the open end of the housing for adistance, said sleeve being adapted for directly resting against saidobject with at least a resting portion of its open end; a sensorpositioned inside said housing adapted for sensing an amount of a forcebetween said sleeve and object when said sleeve rests on the object,said energy application tool passing through said sensor; and ameasuring device coupled to the energy application tool.
 17. The systemof claim 16 further comprising a disposable feature having at least aportion constructed of a material having a minimal effect on thesensitivity of the energy application tool.
 18. The system of claim 16wherein said energy application tool comprises a separable tip.
 19. Thesystem of claim 16, further comprising visual, audible or digital outputmechanisms coupled to said sensor.
 20. The system of claim 16 furthercomprising a tab extending from the sleeve in a direction perpendicularto the resting portion of the open end of the sleeve.